@article{knowles_ju_sennik_mills_jur_2023, title={Simulation techniques for smart textile predictive design}, volume={1266}, ISBN={["*****************"]}, ISSN={["1757-8981"]}, DOI={10.1088/1757-899X/1266/1/012008}, abstractNote={Smart textiles must combine both textile and electronic systems into one product. This presents challenges as each industry has their own design and evaluation standards that are not compatible with one another. As such, smart textile designers tend to rely heavily on the production and iteration of physical prototypes to create a product that meets the specified design criteria. One emerging tool in the apparel industry that has potential to shorten the prototyping cycle is 3D CAD for textiles, also known as 3D garment simulation. While typically used for apparel design and e-commerce, this work presents two case studies that demonstrate how 3D garment simulation can be used as a tool for predictive design of smart textile products. In particular, how strain-dependent properties such as resistance and contact pressure can be predicted and how designs can be optimized to achieve certain performance metrics.}, journal={8TH INTERNATIONAL CONFERENCE ON INTELLIGENT TEXTILES & MASS CUSTOMISATION}, author={Knowles, Caitlin G. and Ju, Beomjun and Sennik, Busra and Mills, Amanda C. and Jur, Jesse S.}, year={2023} } @article{youn_knowles_ju_sennik_mathur_mills_jur_2023, title={Simulation-Based Contact Pressure Prediction Model to Optimize Health Monitoring Using E-Textile Integrated Garment}, volume={23}, ISSN={["1558-1748"]}, url={https://doi.org/10.1109/JSEN.2023.3293065}, DOI={10.1109/JSEN.2023.3293065}, abstractNote={Advancements in wearable technology have integrated textile sensors into garments for long-term electrocardiogram (ECG) monitoring. However, optimizing biosignal quality, motion artifacts, and wearer comfort in electronic textiles (E-textiles) remains challenging. While designing appropriate contact pressure (CP) is crucial, there is a lack of guidance on proper material selection and sizing for achieving the desired CP. This article presents a novel CP prediction model that utilizes three-dimensional garment simulation (3DGS) to optimize knit textiles for health monitoring. First, a stress test method is devised in the simulator to examine the reliability of simulated stress. Based on understanding the simulated stress mechanism, the CP model is developed using simulation parameters. The model is validated against experimental CP values, exhibiting high accuracy ( ${R}^{{2}}= {0.9}$ ). The effectiveness of the CP model is validated through the demonstration of a customized ECG armband incorporating screen-printed dry electrodes on knit fabrics. Analyzing ECG signals, CP, and applied strains validates the benefits of strategically selected materials and sizing. Specifically, the knit sample with 90% polyester and 10% spandex (S-10) for the 15%–20% range and the knit sample with 85% polyester and 18% spandex (S-18) for the 10%–15% strain range significantly enhance ECG quality, resulting in higher signal-to-noise ratios (SNR) of 33.45 (±1.72) and 34.57 (±0.84)−36.61(±1.81), respectively. These design parameters achieve the desired CP range of 1–1.5 kPa, optimizing the functionality and comfort of the ECG armband. The CP model sets a benchmark for the strategic manufacturing of health monitoring garments by integrating digital technology.}, number={16}, journal={IEEE SENSORS JOURNAL}, author={Youn, Seonyoung and Knowles, Caitlin G. and Ju, Beomjun and Sennik, Busra and Mathur, Kavita and Mills, Amanda C. and Jur, Jesse S.}, year={2023}, month={Aug}, pages={18316–18324} } @article{hossain_li_sennik_jur_bradford_2022, title={Adhesive free, conformable and washable carbon nanotube fabric electrodes for biosensing}, volume={6}, ISSN={["2397-4621"]}, DOI={10.1038/s41528-022-00230-3}, abstractNote={Abstract Skin-mounted wearable electronics are attractive for continuous health monitoring and human-machine interfacing. The commonly used pre-gelled rigid and bulky electrodes cause discomfort and are unsuitable for continuous long-term monitoring applications. Here, we design carbon nanotubes (CNTs)-based electrodes that can be fabricated using different textile manufacturing processes. We propose woven and braided electrode design using CNTs wrapped textile yarns which are highly conformable to skin and measure a high-fidelity electrocardiography (ECG) signal. The skin-electrode impedance analysis revealed size-dependent behavior. To demonstrate outstanding wearability, we designed a seamless knit electrode that can be worn as a bracelet. The designed CNT-based dry electrodes demonstrated record high signal-to-noise ratios and were very stable against motion artifacts. The durability test of the electrodes exhibited robustness to laundering and practicality for reusable and sustainable applications.}, number={1}, journal={NPJ FLEXIBLE ELECTRONICS}, author={Hossain, Md. Milon and Li, Braden M. M. and Sennik, Busra and Jur, Jesse S. S. and Bradford, Philip D. D.}, year={2022}, month={Dec} } @article{wu_soltani_sennik_zhou_mackertich-sengerdy_whiting_werner_jur_2022, title={Design of Quasi-Endfire Spoof Surface Plasmon Polariton Leaky-Wave Textile Wearable Antennas}, volume={10}, ISSN={["2169-3536"]}, DOI={10.1109/ACCESS.2022.3218217}, abstractNote={A new design for a quasi-endfire spoof surface plasmon polariton (SSPP) leaky-wave antenna (LWA) is presented for wearable application. The antenna consists of an ultra-thin corrugated metallic structure screen-printed on a flexible textile substrate, which supports extremely confined spoof surface plasmon polaritons. To enable a highly directional leaky mode, two unit-cell designs with different surface impedances are incorporated to realize binary perturbations on the in-plane wavenumber. An auto-adaptive multi-objective optimizer (MOO) is utilized to intelligently design the surface impedance configuration, which achieves significant dimensional reduction compared to the periodically modified SSPP LWAs. A final miniaturized version with 28-unit-cells achieved about 70% size reduction in comparison to the longer design of 75 unit-cells. For proof of concept, the antenna is designed and optimized for operation at 6 GHz. A bandwidth of >200 MHz (5.90 GHz - 6.13 GHz) is achieved, centered around 6 GHz, for which the highly directional endfire pattern can be tilted to 22° and 14° for the 28 and 75 unit-call designs, respectively. The measured results agree well with the simulations. Meanwhile, experimental results show that the Specific Absorption Rate (SAR) is lower than 1.6 W/kg standard when the antenna is 2 mm away from the human phantom. This textile-based antenna realized with advanced screen-printing technology is extremely suitable for garment integration due to its high flexibility, low-profile, good fabrication accuracy, and robustness in its performance.}, journal={IEEE ACCESS}, author={Wu, Yuhao and Soltani, Saber and Sennik, Busra and Zhou, Ying and Mackertich-Sengerdy, Galestan and Whiting, Eric B. and Werner, Douglas H. and Jur, Jesse S.}, year={2022}, pages={115338–115350} } @article{rosenberg_weiner_shahariar_li_peavey_mills_losego_jur_2022, title={Design of a scalable, flexible, and durable thermoelectric cooling device for soft electronics using Kirigami cut patterns}, volume={7}, ISSN={["2058-8585"]}, DOI={10.1088/2058-8585/ac48a0}, abstractNote={A flexible, soft thermoelectric cooling device is presented that shows potential for human cooling applications in wearable technologies and close-to-body applications. Current developments lack integration feasibility due to non-scalable assembly procedures and unsuitable materials for comfortable and durable integration into products. Our devices have been created and tested around the need to conform to the human body which we have quantified through the creation of a repeatable drape testing procedure, a metric used in the textile industry. Inspired by mass manufacturing constraints, our flexible thermoelectric devices are created using commercially available materials and scalable processing techniques. Thermoelectric legs are embedded in a foam substrate to provide flexibility, while Kirigami-inspired cuts are patterned on the foam to provide the drape necessary for mimicking the performance of textile and close to body materials. In total, nine different configurations, three different fill factors and three different Kirigami cut patterns were fabricated and inspected for thermal characterization, mechanical testing, flexibility and drape. Our studies show that adding Kirigami patterns can increase the durability of the device, improve the flexibility, decrease the drape coefficient, and have <1% of impact on cooling performance at higher fill factors (>1.5%), reaching temperature differences up to 4.39 °C ± 0.17 °C between the hot and cold faces of the device. These thermoelectric cooling devices show great flexibility, durability, and cooling for integration into soft cooling products.}, number={1}, journal={FLEXIBLE AND PRINTED ELECTRONICS}, author={Rosenberg, Z. B. and Weiner, N. C. and Shahariar, H. and Li, B. M. and Peavey, J. L. and Mills, A. C. and Losego, M. D. and Jur, J. S.}, year={2022}, month={Mar} } @article{yan_zhou_cheng_orenstein_zhu_yildiz_bradford_jur_wu_dirican_et al._2022, title={Interconnected cathode-electrolyte double-layer enabling continuous Li-ion conduction throughout solid-state Li-S battery}, volume={44}, ISSN={["2405-8297"]}, DOI={10.1016/j.ensm.2021.10.014}, abstractNote={All-solid-state lithium (Li) batteries with high energy density are a promising solution for the next-generation energy storage systems in large-scale devices. To simultaneously overcome the challenges of poor ionic conduction of solid electrolytes and shuttling of active materials, we introduce a functional electrolyte-cathode bilayer framework with interconnected LLAZO channels from the electrolyte into the cathode for advanced solid-state Li-S batteries. Differing from the traditional solid-state batteries with separated layer compositions, the introduced bilayer framework provides ultrafast and continuous ion/electron conduction. Instead of transferring Li+ across the polymer and garnet phases which involve huge interfacial resistance, Li+ is directly conducted through the LLAZO channels created continuously from the cathode layer to the solid electrolyte layer, significantly shortening the diffusion distance and facilitating the redox reaction of sulfur and sulfides. A stable cycle life is demonstrated in the prototype Li-S solid-state batteries assembled with the introduced [email protected] interconnected bilayer framework. High capacity is obtained at room temperature, indicating the superior electrochemical properties of the bilayer framework that result from the unique design of the interconnected LLAZO garnet phase.}, journal={ENERGY STORAGE MATERIALS}, author={Yan, Chaoyi and Zhou, Ying and Cheng, Hui and Orenstein, Raphael and Zhu, Pei and Yildiz, Ozkan and Bradford, Philip and Jur, Jesse and Wu, Nianqiang and Dirican, Mahmut and et al.}, year={2022}, month={Jan}, pages={136–144} } @article{li_reese_ingram_huddleston_jenkins_zaets_reuter_grogg_nelson_zhou_et al._2022, title={Textile-Integrated Liquid Metal Electrodes for Electrophysiological Monitoring}, volume={7}, ISSN={["2192-2659"]}, url={https://doi.org/10.1002/adhm.202200745}, DOI={10.1002/adhm.202200745}, abstractNote={Next generation textile‐based wearable sensing systems will require flexibility and strength to maintain capabilities over a wide range of deformations. However, current material sets used for textile‐based skin contacting electrodes lack these key properties, which hinder applications such as electrophysiological sensing. In this work, a facile spray coating approach to integrate liquid metal nanoparticle systems into textile form factors for conformal, flexible, and robust electrodes is presented. The liquid metal system employs functionalized liquid metal nanoparticles that provide a simple “peel‐off to activate” means of imparting conductivity. The spray coating approach combined with the functionalized liquid metal system enables the creation of long‐term reusable textile‐integrated liquid metal electrodes (TILEs). Although the TILEs are dry electrodes by nature, they show equal skin‐electrode impedances and sensing capabilities with improved wearability compared to commercial wet electrodes. Biocompatibility of TILEs in an in vivo skin environment is demonstrated, while providing improved sensing performance compared to previously reported textile‐based dry electrodes. The “spray on dry—behave like wet” characteristics of TILEs opens opportunities for textile‐based wearable health monitoring, haptics, and augmented/virtual reality applications that require the use of flexible and conformable dry electrodes.}, journal={ADVANCED HEALTHCARE MATERIALS}, author={Li, Braden M. and Reese, Brandon L. and Ingram, Katherine and Huddleston, Mary E. and Jenkins, Meghan and Zaets, Allison and Reuter, Matthew and Grogg, Matthew W. and Nelson, M. Tyler and Zhou, Ying and et al.}, year={2022}, month={Jul} } @article{li_ju_zhou_knowles_rosenberg_flewwellin_kose_jur_2021, title={Airbrushed PVDF-TrFE Fibrous Sensors for E-Textiles}, volume={3}, ISSN={["2637-6113"]}, url={https://doi.org/10.1021/acsaelm.1c00802}, DOI={10.1021/acsaelm.1c00802}, abstractNote={The low-temperature processing, inherent flexibility, and biocompatibility of piezoelectric polymers such as poly(vinylidene fluoride) (PVDF)-based materials enable the creation of soft wearable sensors, energy harvesters, and actuators. Of the various processing techniques, electrospinning is the most widely adopted process to form PVDF nanofiber scaffolds with enhanced piezoelectric properties such that they do not require further post-processing such as mechanical drawing, electrical poling, or thermal annealing. However, electrospinning requires long periods of time to form sufficiently thick PVDF nanofiber scaffolds and requires extremely high voltages to form scaffolds with enhanced piezoelectric properties, which limits the number of usable substrates, thus restricting the integration and use of electrospun PVDF scaffolds into wearable textile platforms. In this work, we propose a facile processing technique to airbrush PVDF–trifluoroethylene (TrFE) nanofiber scaffolds directly onto textile substrates. We tune the polymer concentration (4, 6, and 8 wt %) and the spray distance (5, 12.5, and 20 cm) to understand their effects on the morphology and crystal structure of the fibrous scaffolds. The characterization results show that increasing the polymer wt % encourages the formation of fibrous morphologies and a β-phase crystal structure. We then demonstrate how the airbrushed PVDF–TrFE scaffolds can be easily integrated onto conductive inkjet-printed nonwoven textile substrates to form airbrushed piezoelectric textile devices (APTDs). The APTDs exhibit maximum open-circuit voltages of 667.1 ± 162.1 mV under tapping and 276.9 ± 59.0 mV under bending deformations. The APTDs also show an areal power density of 0.04 μW/cm2, which is 40× times higher compared to previously reported airbrushed PVDF scaffolds. Lastly, we sew APTDs into wearable textile platforms to create fully textile-integrated devices with applications in sensing a basketball shooting form.}, number={12}, journal={ACS APPLIED ELECTRONIC MATERIALS}, publisher={American Chemical Society (ACS)}, author={Li, Braden M. and Ju, Beomjun and Zhou, Ying and Knowles, Caitlin G. and Rosenberg, Zoe and Flewwellin, Tashana J. and Kose, Furkan and Jur, Jesse S.}, year={2021}, month={Dec}, pages={5307–5326} } @article{li_mills_flewwellin_herzberg_bosari_lim_jia_jur_2021, title={Influence of Armband Form Factors on Wearable ECG Monitoring Performance}, volume={21}, ISSN={["1558-1748"]}, DOI={10.1109/JSEN.2021.3059997}, abstractNote={In the current state of innovation in wearable technology, there is a vast array of biomonitoring devices available to record electrocardiogram (ECG) in users, a key indicator of cardiovascular health. Of these devices, armband form factors serve as a convenient all-in-one platform for integration of electronic systems; yet, much of the current literature does not address the appropriate electrode location nor contact pressures necessary to achieve reliable system level ECG sensing. Therefore, this paper will elucidate the role of electrode location and contact pressure on the ECG sensing performance of an electronic textile (E-textile) armband worn on the upper left arm. We first carry out an ECG signal characterization to validate the ideal armband electrode placement necessary to measure high quality signals without sacrificing practical assembly of the armband. We then model and experimentally quantify the contact pressure between the armband onto the upper arm as a function of armband size, a critical parameter dictating skin-electrode impedance and ECG signal quality. Finally, we evaluate how the size of the armband form factor affects its ECG sensing performance. Our experimental results confirm that armbands exhibiting modeled contact pressures between 500 Pa to 1500 Pa can acquire ECG signals. However, armband sizes exhibiting experimental contact pressures of 1297 ± 102 Pa demonstrate the best performance with similar signal-to-noise ratios (SNR) compared to wet electrode benchmarks. The fundamental design parameters discussed in this work serve as a benchmark for the design of future E-textile and wearable form factors with efficient sensing performance.}, number={9}, journal={IEEE SENSORS JOURNAL}, author={Li, Braden M. and Mills, Amanda C. and Flewwellin, Tashana J. and Herzberg, Jacklyn L. and Bosari, Azin Saberi and Lim, Michael and Jia, Yaoyao and Jur, Jesse S.}, year={2021}, month={May}, pages={11046–11060} } @article{ju_kim_li_knowles_mills_grace_jur_2021, title={Inkjet Printed Textile Force Sensitive Resistors for Wearable and Healthcare Devices}, volume={7}, ISSN={["2192-2659"]}, url={https://doi.org/10.1002/adhm.202100893}, DOI={10.1002/adhm.202100893}, abstractNote={Pressure sensors for wearable healthcare devices, particularly force sensitive resistors (FSRs) are widely used to monitor physiological signals and human motions. However, current FSRs are not suitable for integration into wearable platforms. This work presents a novel technique for developing textile FSRs (TFSRs) using a combination of inkjet printing of metal‐organic decomposition silver inks and heat pressing for facile integration into textiles. The insulating void by a thermoplastic polyurethane (TPU) membrane between the top and bottom textile electrodes creates an architectured piezoresistive structure. The structure functions as a simple logic switch where under a threshold pressure the electrodes make contact to create conductive paths (on‐state) and without pressure return to the prior insulated condition (off‐state). The TFSR can be controlled by arranging the number of layers and hole diameters of the TPU spacer to specify a wide range of activation pressures from 4.9 kPa to 7.1 MPa. For a use‐case scenario in wearable healthcare technologies, the TFSR connected with a readout circuit and a mobile app shows highly stable signal acquisition from finger movement. According to the on/off state of the TFSR with LED bulbs by different weights, it can be utilized as a textile switch showing tactile feedback.}, journal={ADVANCED HEALTHCARE MATERIALS}, author={Ju, Beomjun and Kim, Inhwan and Li, Braden M. and Knowles, Caitlin G. and Mills, Amanda and Grace, Landon and Jur, Jesse S.}, year={2021}, month={Jul} } @article{kim_ju_zhou_li_jur_2021, title={Microstructures in All-Inkjet-Printed Textile Capacitors with Bilayer Interfaces of Polymer Dielectrics and Metal-Organic Decomposition Silver Electrodes}, volume={13}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.1c01827}, DOI={10.1021/acsami.1c01827}, abstractNote={Soft printed electronics exhibit unique structures and flexibilities suited for a plethora of wearable applications. However, forming scalable, reliable multilayered electronic devices with heterogeneous material interfaces on soft substrates, especially on porous and anisotropic structures, is highly challenging. In this study, we demonstrate an all-inkjet-printed textile capacitor using a multilayered structure of bilayer polymer dielectrics and particle-free metal-organic decomposition (MOD) silver electrodes. Understanding the inherent porous/anisotropic microstructure of textiles and their surface energy relationship was an important process step for successful planarization. The MOD silver ink formed a foundational conductive layer through the uniform encapsulation of individual fibers without blocking fiber interstices. Urethane-acrylate and poly(4-vinylphenol)-based bilayers were able to form a planarized dielectric layer on polyethylene terephthalate textiles. A unique chemical interaction at the interfaces of bilayer dielectrics performed a significant role in insulating porous textile substrates resulting in high chemical and mechanical durability. In this work, we demonstrate how textiles' unique microstructures and bilayer dielectric layer designs benefit reliability and scalability in the inkjet process as well as the use in wearable electronics with electromechanical performance.}, number={20}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Kim, Inhwan and Ju, Beomjun and Zhou, Ying and Li, Braden M. and Jur, Jesse S.}, year={2021}, month={May}, pages={24081–24094} } @article{ruiz_ridder_fan_gong_li_mills_cobarrubias_strohmaier_jur_lach_2021, title={Self-Powered Cardiac Monitoring: Maintaining Vigilance With Multi-Modal Harvesting and E-Textiles}, volume={21}, ISSN={["1558-1748"]}, DOI={10.1109/JSEN.2020.3017706}, abstractNote={Remote patient monitoring has emerged from the intersection of engineering and medicine. Advances in sensors, circuits and systems have made possible the implementation of small, wearable devices capable of collecting and streaming data for long periods of time to help physicians track diseases and detect conditions in a non-intrusive manner. Cardiac monitoring comprises many of these applications, with the need to capture transient cardiac events motivating the adoption of wearable monitors in standard clinical practice. However, user burden and battery life limit the duration of monitoring or require heavy duty cycling, thus preventing the adoption of these technologies for use cases that require long-term vigilant monitoring, in which the sensor system cannot miss a critical cardiac event. To overcome these challenges, this paper introduces a self-powered system for uninterrupted vigilant cardiac and activity monitoring that senses and streams electrocardiogram (ECG) and motion data continuously to a smartphone while consuming only $683~\mu \text{W}$ on average. To achieve self-powered operation under environmental and wearability constraints, the system incorporates an energy combining technique to support multi-modal energy harvesting from indoor solar and thermoelectric energy. A custom ECG shirt made of a knitted compression fabric with embedded dry electrodes addresses issues of user comfort, skin irritation and motion artifacts. Vigilant Atrial Fibrillation (AF) monitoring is used as an example case study, analyzing sampling frequency and bit-depth quantization and their correlation to vigilant, self-powered operation. The integrated system demonstrates an important step forward for remote patient monitoring beyond the clinic.}, number={2}, journal={IEEE SENSORS JOURNAL}, author={Ruiz, Luis Javier Lopez and Ridder, Matthew and Fan, Dawei and Gong, Jiaqi and Li, Braden Max and Mills, Amanda C. and Cobarrubias, Elizabeth and Strohmaier, Jason and Jur, Jesse S. and Lach, John}, year={2021}, month={Jan}, pages={2263–2276} } @article{zheng_jur_cheng_2021, title={Smart materials and devices for electronic textiles}, ISSN={["1938-1425"]}, DOI={10.1557/s43577-021-00120-5}, abstractNote={Abstract Electronic textiles (e-textiles) have attracted a significantly increasing amount of interest in recent years. A wide variety of e-textile devices, systems, and applications have been reported. The development of smart materials and devices has played a critical role in this rapid progress of e-textiles. This article provides a concise review of the development of e-textiles and their applications. It introduces the three articles included in this issue. Finally, it discusses the challenges of this field. Graphic abstract}, journal={MRS BULLETIN}, author={Zheng, Zijian and Jur, Jesse and Cheng, Wenlong}, year={2021}, month={Jun} } @article{martinez_mao_vital_shahariar_werner_jur_bhardwaj_2020, title={Compact, Low-Profile and Robust Textile Antennas With Improved Bandwidth for Easy Garment Integration}, volume={8}, ISSN={["2169-3536"]}, DOI={10.1109/ACCESS.2020.2989260}, abstractNote={In this paper, a compact and low-profile proximity-fed textile-based antenna with robust performance and improved bandwidth is proposed for body-area network (BAN) applications. The employed proximity-fed antenna differs from traditional wearable antennas in the sense that it not only exhibits improved bandwidth but also a reduced footprint. The proposed antenna also possesses an extreme robustness when subject to structural deformation and human body loading effects. In addition, the impact of the uncertainty in the dielectric constant (a characteristic associated with most textile material systems) is investigated for the first time. Experimental results show that the proposed proximity-fed antenna outperforms wearable antennas that employ more conventional feeding methodologies. The antenna was fabricated using two different flexible textile-based material systems (i.e., one printed and one embroidered). The advantages and disadvantages of each fabrication approach are discussed. The proposed antenna is characterized in free-space and on a human body, yielding robust performance in both cases.}, journal={IEEE ACCESS}, author={Martinez, Idellyse and Mao, Chun-Xu and Vital, Dieff and Shahariar, Hasan and Werner, Douglas H. and Jur, Jesse S. and Bhardwaj, Shubhendu}, year={2020}, pages={77490–77500} } @article{shahariar_kim_bhakta_jur_2020, title={Direct-write printing process of conductive paste on fiber bulks for wearable textile heaters}, volume={29}, ISSN={["1361-665X"]}, DOI={10.1088/1361-665X/ab8c25}, abstractNote={In the printing of electronic materials for electronic textiles (e-textiles), reliability and durability of devices are of critical importance. A unique capability of a direct-write (DW) printing process is introduced that takes advantage of ink penetration in fiber bulks, owed in part to the capillary action phenomena of conductive inks on the textile. As a result of the penetration, the durability of the printed patterns improved in deformability and washability. To understand this phenomenon, the ink-to-substrate interaction of the Ag-based conductive ink on thermoplastic polyurethane (TPU) films, polyethylene terephthalate (PET) nonwoven textiles, and nylon-PET nonwoven (Evolon®) textiles are studied. Substrate properties such as surface roughness and porosity show a significant impact on the flow properties of the ink. The penetration of the conductive ink into the fiber bulk created a unique fiber-ink composite structure that is structurally more stable under mechanical deformation. Due to the high porosity and penetration to the cross-sectional direction, the patterns on the PET nonwoven textiles showed less ink spreading on the surface and higher resistance compared to a densely structured Evolon® textiles. The printed patterns were demonstrated as wearable textile heaters and showed reliable performance during mechanical deformation, wash, and cyclic heating tests. Finally, a printed heater wrap was demonstrated on the human body to explain a use case scenario for the DW process for wearable electronics.}, number={8}, journal={SMART MATERIALS AND STRUCTURES}, author={Shahariar, Hasan and Kim, Inhwan and Bhakta, Raj and Jur, Jesse S.}, year={2020}, month={Aug} } @article{rich_camatcho_stephenson_crew_jur_gorga_2020, title={Evaluation of Infrared Absorption on Thermal Properties of Modified Modacrylic Fibers}, volume={7}, ISSN={["2330-5517"]}, DOI={10.14504/ajr.7.2.5}, abstractNote={A novel modacrylic fiber with the capability to absorb ∼80% of all infrared radiation was evaluated for use in personal thermal comfort applications. Using an infrared (IR) imaging camera to monitor optical changes over time and heat flux measurements, it was concluded that this altered modacrylic fiber possesses both a unique thermal signature as well as increased heat flux compared to 100% cotton. A design of experiments (DOE) was conducted to determine if blending this material with other fibers would result in a fabric with a higher thermal conductivity. It was observed that blends of nylon and the altered modacrylic tended to have the highest conductivity and would provide a cooling effect if used in a garment.}, number={2}, journal={AATCC JOURNAL OF RESEARCH}, author={Rich, Hannah Alexis and Camatcho, Amor M. and Stephenson, Hannah Jean and Crew, Jacob and Jur, Jesse S. and Gorga, Russell E.}, year={2020}, month={Mar} } @article{li_yildiz_mills_flewwellin_bradford_jur_2020, title={Iron-on carbon nanotube (CNT) thin films for biosensing E-Textile applications}, volume={168}, ISSN={["1873-3891"]}, DOI={10.1016/j.carbon.2020.06.057}, abstractNote={Conductive carbon nanotube-thermoplastic polyurethane (CNT-TPU) composite thin films are patterned and integrated onto knitted textile substrates to form electronic textile (E-Textile) dry electrodes. Vertically aligned CNT arrays are mechanically drawn into thin CNT sheets and infiltrated with a TPU solution to form the CNT-TPU thin films. The CNT-TPU thin films are then heat laminated onto knitted textile substrates to form dry E-Textile electrodes. To understand the wearability of our CNT-TPU thin films we perform an in-depth analysis of the films’ electromechanical properties, electrical impedance, and electrocardiogram (ECG) sensing performance. The electromechanical coupling between the CNT thin films and knitted textile substrates show a strong anisotropic dependence between the CNT film alignment and textile knit structure. Further analysis into the CNT thin films reveal that larger electrode sizes with a larger number of CNT sheet layers in the film, lead to more favorable impedance behaviors and ECG sensing capabilities. As a wearable demonstration, we fabricate a textile arm sleeve integrated with CNT thin film electrodes to form an ECG sensing E-Textile system. The proposed E-Textile sleeve demonstrates the practicality of our CNT thin films and show promise for other E-Textile and wearable applications.}, journal={CARBON}, author={Li, Braden M. and Yildiz, Ozkan and Mills, Amanda C. and Flewwellin, Tashana J. and Bradford, Philip D. and Jur, Jesse S.}, year={2020}, month={Oct}, pages={673–683} } @article{aksu_bradford_jur_2020, title={Microfluidic Behavior of Alumina Nanotube-Based Pathways within Hydrophobic CNT Barriers}, volume={36}, ISSN={["0743-7463"]}, DOI={10.1021/acs.langmuir.0c01096}, abstractNote={The use of porous micro-and nanostructured materials within microfluidic devices provides opportunities for unique fluid transport characteristics. In this paper we investigate the microfluidic behavior of hybrid alumina nanotube-based pathways within hydrophobic carbon nanotube (CNT) barriers. These hybrid systems provide unique benefits toward the potential liquid transport control in porous structures with real-time sensing of those fluids. Specifically, we examine how the alignment of the alumina nanostructures with high internal porosity enables increasing capillary action and the sensitivity of detection. Based on the Lucas and Washburn model (LW) and modified LW models, the microfluidic behavior of these systems is detailed. The predictions from the models for the time exponent for capillary transport in porous media is shown to be ≤ 0.5. The experimental results demonstrate that the average capillary rise in nanostructured media driven by capillary force follows t0.7. The hydrophilic/electrically insulating and hydrophobic/electrically conductive patterned structures of the device are applied toward electronic measurement within the microfluidic channels. The device structure enables detection of fluid samples of very low analyte concentrations (1 µM) that can be achieved due to the very high surface area of the hybrid structure combined with the electrical conductivity of CNT support structure.}, number={30}, journal={LANGMUIR}, author={Aksu, Cemile and Bradford, Philip D. and Jur, Jesse S.}, year={2020}, month={Aug}, pages={8792–8799} } @article{sadeghifar_venditti_pawlak_jur_2019, title={Bi-component carbohydrate and lignin nanoparticle production from bio-refinery lignin: A rapid and green method}, volume={14}, ISSN={1930-2126 1930-2126}, url={http://dx.doi.org/10.15376/biores.14.3.6179-6185}, DOI={10.15376/biores.14.3.6179-6185}, abstractNote={A rapid and green preparation of lignin nanoparticles was demonstrated starting from bio-refinery lignin containing grafted carbohydrates. The particles were prepared by recovering a fraction of the lignin, which contained 24% carbohydrate (by weight) as the insoluble fraction in 0.5 M NaOH. The carbohydrate content of this fraction was verified with a wet chemistry analytical technique, nuclear magnetic resonance, and X-ray diffraction. This fraction was then dissolved in a NaOH/urea/water system and added dropwise to water under a high shear, which rapidly formed precipitated particles in a size range of approximately 100 nm. This carbohydrate-containing fraction of the lignin was soluble in a green solvent system that was not suited for lignin alone. The generated particles were stable in different organic solvents and water. Overall, the dissolution of the bio-refinery lignin in the NaOH/urea/water system, followed by precipitation in water can be regarded as a green and rapid method to produce stable nanoparticles. The generated nanoparticles, containing both carbohydrates and lignin, are expected to have unique applications because of their bi-component nature. Furthermore, this is the first publication to show how materials with high levels of lignin can be solubilized in solvents that are conventionally used for cellulose.}, number={3}, journal={BioResources}, publisher={BioResources}, author={Sadeghifar, Hasan and Venditti, Richard A. and Pawlak, Joel J. and Jur, Jesse}, year={2019}, month={Jun}, pages={6179–6185} } @article{sadeghifar_venditti_pawlak_jur_2019, title={Cellulose Transparent and Flexible Films Prepared from DMAc/LiCl Solutions}, volume={14}, ISSN={["1930-2126"]}, DOI={10.15376/biores.14.4.9021-9032}, abstractNote={Cellulose transparent and flexible film was prepared by dissolving micro-crystalline cellulose powder in Dimethylacetamide/Lithium Chloride (DMAc/LiCl) followed by regeneration in acetone and subsequent washing with water. The solution was cast on a glass plate. The interactions of water molecules and the swollen cellulose in the gel were examined by differential scanning calorimetry, DSC. An increased melting point of water in the gel indicated the presence of stronger bonding between water and cellulose than in the non-modified cellulose. The prepared dried films had 63 g/m2 weight and 0.06 mm thickness with 1.14 g/cm3 density.The prepared dry film exhibited high transparency, around 95% with visible light. The transparency and mechanical properties of the films were stable at high temperature (120°C) and exposure to UV irradiation. Thermal analysis of the prepared sample indicated film stability up to 275 °C. The tensile strength of the cellulose film was around 120 MPa with about 10% strain to break. The mechanical properties of the films were stable in alkali and acidic solutions.}, number={4}, journal={BIORESOURCES}, author={Sadeghifar, Hasan and Venditti, Richard and Pawlak, Joel J. and Jur, Jesse}, year={2019}, month={Nov}, pages={9021–9032} } @article{shahariar_kim_soewardiman_jur_2019, title={Inkjet Printing of Reactive Silver Ink on Textiles}, volume={11}, ISSN={["1944-8252"]}, DOI={10.1021/acsami.8b18231}, abstractNote={Inkjet printing of functional inks on textiles to embed passive electronics devices and sensors is a novel approach in the space of wearable electronic textiles. However, achieving functionality such as conductivity by inkjet printing on textiles is challenged by the porosity and surface roughness of textiles. Nanoparticle-based conductive inks frequently cause blockage/clogging of inkjet printer nozzles, making it a less than ideal method for applying these functional materials. It is also very challenging to create a conformal conductive coating and achieve electrically conductive percolation with the inkjet printing of metal nanoparticle inks on rough and porous textile and paper substrates. Herein, a novel reliable and conformal inkjet printing process is demonstrated for printing particle-free reactive silver ink on uncoated polyester textile knit, woven, and nonwoven fabrics. The particle-free functional ink can conformally coat individual fibers to create a conductive network within the textile structure without changing the feel, texture, durability, and mechanical behavior of the textile. It was found that the conductivity and the resolution of the inkjet-printed tracks are directly related with the packing and the tightness of fabric structures and fiber sizes of the fabrics. It is noteworthy that the electrical conductivity of the inkjet-printed conductive coating on pristine polyethylene terephthalate fibers is improved by an order of magnitude by in situ heat-curing of the textile surface during printing as the in situ heat-curing process minimizes the wicking of the ink into the textile structures. A minimum sheet resistance of 0.2 ± 0.025 and 0.9 ± 0.02 Ω/□ on polyester woven and polyester knit fabrics is achieved, respectively. These findings aim to advance E-textile product design through integration of inkjet printing as a low-cost, scalable, and automated manufacturing process.}, number={6}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Shahariar, Hasan and Kim, Inhwan and Soewardiman, Henry and Jur, Jesse S.}, year={2019}, month={Feb}, pages={6208–6216} } @article{kim_shahariar_ingram_zhou_jur_2019, title={Inkjet Process for Conductive Patterning on Textiles: Maintaining Inherent Stretchability and Breathability in Knit Structures}, volume={29}, ISSN={["1616-3028"]}, url={http://dx.doi.org/10.1002/adfm.201807573}, DOI={10.1002/adfm.201807573}, abstractNote={Abstract}, number={7}, journal={ADVANCED FUNCTIONAL MATERIALS}, publisher={Wiley}, author={Kim, Inhwan and Shahariar, Hasan and Ingram, Wade F. and Zhou, Ying and Jur, Jesse S.}, year={2019}, month={Feb} } @article{ingram_jur_2019, title={Properties and Applications of Vapor Infiltration into Polymeric Substrates}, volume={71}, ISSN={["1543-1851"]}, DOI={10.1007/s11837-018-3157-9}, number={1}, journal={JOM}, author={Ingram, Wade F. and Jur, Jesse S.}, year={2019}, month={Jan}, pages={238–245} } @article{shahariar_jur_2018, title={Correlation of printing faults with the RF characteristics of coplanar waveguides (CPWs) printed on nonwoven textiles}, volume={273}, ISSN={["0924-4247"]}, DOI={10.1016/j.sna.2018.02.043}, abstractNote={Printing high-resolution microwave passive devices directly on textile surfaces presents many challenges due to the high surface roughness and porosity of textile materials. This paper explains in detail physical and electromagnetic characterization of screen-printed coplanar waveguides (CPWs) on nonwoven textiles with a surface roughness of approximately ∼18 μm. Three different screen mesh counts (mesh opening unit) are used to screen print CPWs with five different resolutions. A screen printable silver paste is used as a conductive ink during the screen printing process. The difference in screen mesh counts affects the line resolution, thickness, conformity, and overall power transferring capacity of printed CPWs. A print resolution of 220 μm as the gap between the parallel lines of CPWs is achieved in this work without any surface modification of textile media. The surface roughness of the printed silver track is very similar to the base fabric (18 μm) when the screen with 305 mesh-count is selected for printing. Additionally, the thickness of the ink on the fabric is most conformal and lowest (23.4 μm) for the similar selection of screen mesh count. Fabricated CPWs are characterized for signals from 0.5 GHz to 10 GHz and compared to electromagnetic 3D simulation results. This paper also identifies minute printing faults in the 3D structure of the printed CPWs and correlates that with the scattering parameters of the transmission lines. Simulated and experimental data prove that a well-designed and process optimized printed nonwoven-based CPW works well (i.e. below 3 dB of insertion loss) for frequencies ranging from 0.5 GHz to 7 GHz.}, journal={SENSORS AND ACTUATORS A-PHYSICAL}, author={Shahariar, Hasan and Jur, Jesse S.}, year={2018}, month={Apr}, pages={240–248} } @article{aksu_ingram_bradford_jur_2018, title={Laser-etch patterning of metal oxide coated carbon nanotube 3D architectures}, volume={29}, ISSN={["1361-6528"]}, DOI={10.1088/1361-6528/aac79d}, abstractNote={This paper describes a way to fabricate novel hybrid low density nanostructures containing both carbon nanotubes (CNTs) and ceramic nanotubes. Using atomic layer deposition, a thin film of aluminum oxide was conformally deposited on aligned multiwall CNT foams in which the CNTs make porous, three-dimensional interconnected networks. A CO2 laser was used to etch pure alumina nanotube structures by burning out the underlying CNT substrate in discrete locations via the printed laser pattern. Structural and morphological transitions during the calcination process of aluminum oxide coated CNTs were investigated through in situ transmission electron microscopy and high-resolution scanning electron microscopy. Laser parameters were optimized to etch the CNT away (i.e. etching speed, power and focal length) while minimizing damage to the alumina nanotubes due to overheating. This study opens a new route for fabricating very low density three dimensionally patterned materials with areas of dissimilar materials and properties. To demonstrate the attributes of these structures, the etched areas were used toward anisotropic microfluidic liquid flow. The demonstration used the full thickness of the material to make complex pathways for the liquid flow in the structure. Through tuning of processing conditions, the alumina nanotube (etched) regions became hydrophilic while the bulk material remained hydrophobic and electrically conductive.}, number={33}, journal={NANOTECHNOLOGY}, author={Aksu, Cemile and Ingram, Wade and Bradford, Philip D. and Jur, Jesse S.}, year={2018}, month={Aug} } @article{faraji_stano_akyildiz_yildiz_jur_bradford_2018, title={Modifying the morphology and properties of aligned CNT foams through secondary CNT growth}, volume={29}, ISSN={["1361-6528"]}, DOI={10.1088/1361-6528/aac03c}, abstractNote={In this work, we report for the first time, growth of secondary carbon nanotubes (CNTs) throughout a three-dimensional assembly of CNTs. The assembly of nanotubes was in the form of aligned CNT/carbon (ACNT/C) foams. These low-density CNT foams were conformally coated with an alumina buffer layer using atomic layer deposition. Chemical vapor deposition was further used to grow new CNTs. The CNT foam’s extremely high porosity allowed for growth of secondary CNTs inside the bulk of the foams. Due to the heavy growth of new nanotubes, density of the foams increased more than 2.5 times. Secondary nanotubes had the same graphitic quality as the primary CNTs. Microscopy and chemical analysis revealed that the thickness of the buffer layer affected the diameter, nucleation density as well as growth uniformity across the thickness of the foams. The effects of secondary nanotubes on the compressive mechanical properties of the foams was also investigated.}, number={29}, journal={NANOTECHNOLOGY}, author={Faraji, Shaghayegh and Stano, Kelly and Akyildiz, Halil and Yildiz, Ozkan and Jur, Jesse S. and Bradford, Philip D.}, year={2018}, month={Jul} } @article{ingram_halbur_madan_jur_2018, title={Photoremediation of heavy metals from aqueous environments onto ZnO coated fibrous polyethylene terephthalate nonwovens}, volume={36}, ISSN={["1520-8559"]}, DOI={10.1116/1.5016172}, abstractNote={This work explores the photoremediation of hexavalent chromium from aqueous solutions on to nonwoven polyethylene terephthalate substrates modified by nanoscale atomic layer deposition coatings of ZnO. Removal of Cr6+ is observed to increase with ZnO thin film thickness up to 500 atomic layer deposition cycles (∼90 nm) with a maximum Cr6+ removal of 67% after an exposure of 540 J/cm2. Instead of reducing Cr6+ to Cr3+, this work shows that the mechanism for removal of the Cr ion from solution is by sorption and photoreduction of the metal onto the ZnO surface. Additionally, mixed solutions with Cr6+ and As3+ ions were tested for simultaneous photoreduction and photooxidation, showing that mixed ion solutions may better utilize photogenerated electrons and holes, simultaneously. The reported demonstration and analysis represents a facile route for reclamation of toxic components in an aqueous media.}, number={3}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Ingram, Wade F. and Halbur, Jonathan C. and Madan, Ankesh and Jur, Jesse S.}, year={2018}, month={May} } @article{sadeghifar_venditti_jur_gorga_pawlak_2017, title={Cellulose-Lignin Biodegradable and Flexible UV Protection Film}, volume={5}, ISSN={2168-0485 2168-0485}, url={http://dx.doi.org/10.1021/acssuschemeng.6b02003}, DOI={10.1021/acssuschemeng.6b02003}, abstractNote={There is significant interest in biodegradable and transparent UV protection films from renewable resources for many different applications. Herein, the preparation and characterization of semitransparent flexible cellulose films containing low amounts of covalently bonded lignin with UV-blocking properties are described. Azide modified cellulose dissolved in dimethylacetamide/lithium chloride (DMAc/LiCl) was reacted with propargylated lignin to produce 0.5%, 1%, and 2% by weight lignin containing materials. Cellulose-lignin films were prepared by regeneration in acetone. These covalently bonded cellulose-lignin films were homogeneous, unlike the simple blends of cellulose and lignin. Prepared films showed high UV protection ability. Cellulose film containing 2% lignin showed 100% protection of UV-B (280–320 nm) and more than 90% of UV-A (320–400 nm). The UV protection of prepared films was persistent when exposed to thermal treatment at 120 °C and UV irradiation. Thermogravimetric analysis of the films s...}, number={1}, journal={ACS Sustainable Chemistry & Engineering}, publisher={American Chemical Society (ACS)}, author={Sadeghifar, Hasan and Venditti, Richard and Jur, Jesse and Gorga, Russell E. and Pawlak, Joel J.}, year={2017}, month={Nov}, pages={625–631} } @article{farahbakhsh_shahbeigi-roodposhti_sadeghifar_venditti_jur_2017, title={Effect of isolation method on reinforcing capability of recycled cotton nanomaterials in thermoplastic polymers}, volume={52}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-016-0738-2}, number={9}, journal={Journal of Materials Science}, author={Farahbakhsh, N. and Shahbeigi-Roodposhti, P. and Sadeghifar, H. and Venditti, R.A. and Jur, J.S.}, year={2017}, pages={4997–5013} } @inproceedings{shahariar_soewardiman_jur_2017, title={Fabrication and packaging of flexible and breathable patch antennas on textiles}, DOI={10.1109/secon.2017.7925306}, abstractNote={Textile antennas are prone to damage and change their shape and RF (radio frequency) characteristics over time. However, typical hydrophobic coatings or encapsulation layers, such as polyurethane, acrylate, or films, make textile antennas rigid and air impermeable. This work details the approach of using a polyurethane web as an encapsulation and lamination layer for screen-printed microstrip patch antennas on textile fabrics. Integrating the polyurethane web into the textile antennas makes the printed antennas flexible, air permeable, and durable. Further improvements are made by introducing a novel porous patch antenna design to enhance the flexibility and air-permeability for printed antennas. Antennas were designed and modeled using the ANSYS HFSS simulation software and compared with fabricated experimental results. Results show the fully packaged printed antenna have good impedance matching even under different bent conditions. The antennas were also analyzed before and after rinsing with heavy flow of water for 2 minutes to determine the effect of wetting.}, booktitle={Southeastcon 2017}, author={Shahariar, H. and Soewardiman, H. and Jur, J. S.}, year={2017} } @article{myers_hodges_jur_2017, title={Human and environmental analysis of wearable thermal energy harvesting}, volume={143}, ISSN={["1879-2227"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85017181906&partnerID=MN8TOARS}, DOI={10.1016/j.enconman.2017.04.002}, abstractNote={In considering wearable energy harvesting, one must recognize the wide array of factors that lead to variations of energy harvesting. The objective of this work is to define analytical methods to study the effect of environmental and human factors on thermal energy generator (TEG) performance in a variety of use case scenarios. A test method for evaluating the performance of a TEG in a wearable form is developed and demonstrated using both in-lab and out-of-lab procedures. The fabrication procedure of an energy harvesting wearable device demonstrates a method of integrating rigid devices into a flexible substrate. The wearable device is used in a human trial which covered a series of activities in different environmental conditions. The results of these trials demonstrate the significant effect of movement, or convection, on thermal energy harvesting. Humidity levels do not have a significant correlation to power; however, wet bulb temperature must be taken into consideration due to the additional cooling effect of evaporation on temperature. The data collected indicates that while dry-bulb temperature does not have the greatest effect on TEG power generation, wet-bulb temperature is indicative of TEG performance. Additionally, user generated movement is the main consideration when designing a wearable device with TEGs as it had the largest effects on power generation. The results of this work quantify how a wearable device will perform throughout daily activities, allowing the definition of an operational scenario of a self-powered wearable device while choosing the most appropriate design for a particular application. This work also provides a foundation for exploring how textiles can enable the design of unique wearable devices. This will lead to further investigation into quantifying the effect that the construction of a textile has on TEG performance as well as on consumer comfort.}, journal={ENERGY CONVERSION AND MANAGEMENT}, author={Myers, Amanda and Hodges, Ryan and Jur, Jesse S.}, year={2017}, month={Jul}, pages={218–226} } @article{iezzi_ankireddy_twiddy_losego_jur_2017, title={Printed, metallic thermoelectric generators integrated with pipe insulation for powering wireless sensors}, volume={208}, ISSN={["1872-9118"]}, DOI={10.1016/j.apenergy.2017.09.073}, abstractNote={The Internet of Things (IoT), coupled with advanced analytics, is poised to revolutionize manufacturing maintenance and efficiency. However, a practical route to powering these many IoT devices remains unclear. In this work, flexible thermoelectric generators (TEGs) are fabricated from low cost, screen printed silver and nickel inks before being integrated into a novel form factor device based on commercial steam pipe insulation. Through optimization of internal resistances and total device design, this 420-junction TEG device produces 308 µW of power at a temperature difference of 127 K. This is sufficient to power a temperature sensing circuit with wireless communication capabilities. In this report we demonstrate that, after an initial 4 h of charging, this TEG can power a standard RFduino microcontroller for 10 min while sending temperature readings every 30 s via Bluetooth Low Energy (BLE) to a cell phone. Additional optimization and scaling could further increase system efficiency and provide a viable route to powering an industrial wireless sensing network (WSN).}, journal={APPLIED ENERGY}, author={Iezzi, Brian and Ankireddy, Krishnamraju and Twiddy, Jack and Losego, Mark D. and Jur, Jesse S.}, year={2017}, month={Dec}, pages={758–765} } @article{stano_faraji_yildiz_akyildiz_bradford_jur_2017, title={Strong and resilient alumina nanotube and CNT/alumina hybrid foams with tuneable elastic properties}, volume={7}, ISSN={["2046-2069"]}, DOI={10.1039/c7ra02452e}, abstractNote={Alumina foams from anisotropic structured carbon nanotube structures are studied for their unique mechanical and thermal performance characteristics.}, number={45}, journal={RSC ADVANCES}, author={Stano, Kelly L. and Faraji, Shaghayegh and Yildiz, Ozkan and Akyildiz, Halil and Bradford, Philip D. and Jur, Jesse S.}, year={2017}, pages={27923–27931} } @article{heo_kim_ban_kim_lee_jur_kim_kim_hong_park_2017, title={Thread-Like CMOS Logic Circuits Enabled by Reel-Processed Single-Walled Carbon Nanotube Transistors via Selective Doping}, volume={29}, ISSN={["1521-4095"]}, DOI={10.1002/adma.201701822}, abstractNote={The realization of large‐area electronics with full integration of 1D thread‐like devices may open up a new era for ultraflexible and human adaptable electronic systems because of their potential advantages in demonstrating scalable complex circuitry by a simply integrated weaving technology. More importantly, the thread‐like fiber electronic devices can be achieved using a simple reel‐to‐reel process, which is strongly required for low‐cost and scalable manufacturing technology. Here, high‐performance reel‐processed complementary metal‐oxide‐semiconductor (CMOS) integrated circuits are reported on 1D fiber substrates by using selectively chemical‐doped single‐walled carbon nanotube (SWCNT) transistors. With the introduction of selective n‐type doping and a nonrelief photochemical patterning process, p‐ and n‐type SWCNT transistors are successfully implemented on cylindrical fiber substrates under air ambient, enabling high‐performance and reliable thread‐like CMOS inverter circuits. In addition, it is noteworthy that the optimized reel‐coating process can facilitate improvement in the arrangement of SWCNTs, building uniformly well‐aligned SWCNT channels, and enhancement of the electrical performance of the devices. The p‐ and n‐type SWCNT transistors exhibit field‐effect mobility of 4.03 and 2.15 cm2 V−1 s−1, respectively, with relatively narrow distribution. Moreover, the SWCNT CMOS inverter circuits demonstrate a gain of 6.76 and relatively good dynamic operation at a supply voltage of 5.0 V.}, number={31}, journal={ADVANCED MATERIALS}, author={Heo, Jae Sang and Kim, Taehoon and Ban, Seok-Gyu and Kim, Daesik and Lee, Jun Ho and Jur, Jesse S. and Kim, Myung-Gil and Kim, Yong-Hoon and Hong, Yongtaek and Park, Sung Kyu}, year={2017}, month={Aug} } @article{ankireddy_menon_iezzi_yee_losego_jur_2016, title={Electrical Conductivity, Thermal Behavior, and Seebeck Coefficient of Conductive Films for Printed Thermoelectric Energy Harvesting Systems}, volume={45}, ISSN={["1543-186X"]}, DOI={10.1007/s11664-016-4780-2}, number={11}, journal={JOURNAL OF ELECTRONIC MATERIALS}, author={Ankireddy, Krishnamraju and Menon, Akanksha K. and Iezzi, Brian and Yee, Shannon K. and Losego, Mark D. and Jur, Jesse S.}, year={2016}, month={Nov}, pages={5561–5569} } @article{yokus_jur_2016, title={Fabric-Based Wearable Dry Electrodes for Body Surface Biopotential Recording}, volume={63}, ISSN={["1558-2531"]}, DOI={10.1109/tbme.2015.2462312}, abstractNote={A flexible and conformable dry electrode design on nonwoven fabrics is examined as a sensing platform for biopotential measurements. Due to limitations of commercial wet electrodes (e.g., shelf life, skin irritation), dry electrodes are investigated as the potential candidates for long-term monitoring of ECG signals. Multilayered dry electrodes are fabricated by screen printing of Ag/AgCl conductive inks on flexible nonwoven fabrics. This study focuses on the investigation of skin-electrode interface, form factor design, electrode body placement of printed dry electrodes for a wearable sensing platform. ECG signals obtained with dry and wet electrodes are comparatively studied as a function of body posture and movement. Experimental results show that skin-electrode impedance is influenced by printed electrode area, skin-electrode interface material, and applied pressure. The printed electrode yields comparable ECG signals to wet electrodes, and the QRS peak amplitude of ECG signal is dependent on printed electrode area and electrode on body spacing. Overall, fabric-based printed dry electrodes present an inexpensive health monitoring platform solution for mobile wearable electronics applications by fulfilling user comfort and wearability.}, number={2}, journal={IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING}, author={Yokus, Murat A. and Jur, Jesse S.}, year={2016}, month={Feb}, pages={423–430} } @article{myers_hodges_jur_2016, title={Human and Environment Influences on Thermoelectric Energy Harvesting Toward Self-Powered Textile-Integrated Wearable Devices}, volume={1}, ISSN={["2059-8521"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85041362992&partnerID=MN8TOARS}, DOI={10.1557/adv.2016.316}, abstractNote={The study of on-body energy harvesting is most often focused on improving and optimizing the energy harvester. However, other factors play a critical factor in the energy harvesting integration techniques of the harvester to close-to body materials of the wearable device. In addition, one must recognize the wide array of human factors and ergonomic factors that lead a variation of the energy harvesting. In this work, key affecting variables at varying on-body locations are investigated for commercial thermoelectric generators (TEGs) integrated within a textile-based wearable platform. For this study, a headband and an armband is demonstrated with five TEGs connected in series in a flexible form factor via Pyralux®. These platforms enable comparison of the amount of energy harvested from the forehead versus the upper arm during various external conditions and movement profiles, e.g. running, walking, and stationary for periods of up to 60 minutes. During these tests, ambient temperature, ambient humidity, accelerometry, and instantaneous power are recorded live during the activity and correlated to the energy harvested. Human factors such as skin temperature and application pressure were also analyzed. Our analysis demonstrates that vigorous movement can generate over 100 μW of instantaneous power from the headband and up to 35 μW from the armband. During the stationary movement profile, the instantaneous power levels of both the headband and the armband decreased to a negligible value. Our studies show that for higher intensities of movement, air convection on the cool side of the TEG is the dominating variable whereas the temperature gradient has a significant effect when the subject is stationary. This work demonstrates key materials and design factors in on-body thermoelectric energy harvesting that allows for a strategic approach to improving the integration of the TEGs.}, number={38}, journal={MRS ADVANCES}, author={Myers, Amanda and Hodges, Ryan and Jur, Jesse S.}, year={2016}, pages={2665–2670} } @article{akyildiz_stano_roberts_everitt_jur_2016, title={Photoluminescence Mechanism and Photocatalytic Activity of Organic-Inorganic Hybrid Materials Formed by Sequential Vapor Infiltration}, volume={32}, ISSN={["0743-7463"]}, DOI={10.1021/acs.langmuir.6b00285}, abstractNote={Organic-inorganic hybrid materials formed by sequential vapor infiltration (SVI) of trimethylaluminum into polyester fibers are demonstrated, and the photoluminescence of the fibers is evaluated using a combined UV-vis and photoluminescence excitation (PLE) spectroscopy approach. The optical activity of the modified fibers depends on infiltration thermal processing conditions and is attributed to the reaction mechanisms taking place at different temperatures. At low temperatures a single excitation band and dual emission bands are observed, while, at high temperatures, two distinct absorption bands and one emission band are observed, suggesting that the physical and chemical structure of the resulting hybrid material depends on the SVI temperature. Along with enhancing the photoluminescence intensity of the PET fibers, the internal quantum efficiency also increased to 5-fold from ∼4-5% to ∼24%. SVI processing also improved the photocatalytic activity of the fibers, as demonstrated by photodeposition of Ag and Au metal particles out of an aqueous metal salt solution onto fiber surfaces via UVA light exposure. Toward applications in flexible electronics, well-defined patterning of the metallic materials is achieved by using light masking and focused laser rastering approaches.}, number={17}, journal={LANGMUIR}, author={Akyildiz, Halil I. and Stano, Kelly L. and Roberts, Adam T. and Everitt, Henry O. and Jur, Jesse S.}, year={2016}, month={May}, pages={4289–4296} } @article{yokus_foote_jur_2016, title={Printed Stretchable Interconnects for Smart Garments: Design, Fabrication, and Characterization}, volume={16}, ISSN={["1558-1748"]}, DOI={10.1109/jsen.2016.2605071}, abstractNote={This paper explores stretchability and fatigue life of inexpensive printed stretchable interconnects for smart garments. Multilayer stretchable interconnects are created on a knit fabric by screen printing of Ag/AgCl conductive inks on thermoplastic polyurethane film (TPU). Heat lamination of this layer onto a knit fabric and its protective encapsulation with a second TPU layer yields a multilayer stretchable interconnect structure. Design and optimization of the printed meandering interconnects are performed experimentally. The effect of processing steps, area of substrate, and encapsulation layers on the electro-mechanical properties of the stretchable interconnects are investigated. Washing endurance of the printed lines is also explored. The meandering stretchable printed line demonstrates stretchability of over 100% strain and fatigue life of 1000 cycles at 20% strain. Washing endurance of 100 cycles is reported. This paper presents an inexpensive method of realization of electronics integration on textiles by maintaining textile comfort and wearability.}, number={22}, journal={IEEE SENSORS JOURNAL}, author={Yokus, Murat A. and Foote, Rachel and Jur, Jesse S.}, year={2016}, month={Nov}, pages={7967–7976} } @article{halbur_padbury_jur_2016, title={Silver decorated polymer supported semiconductor thin films by UV aided metalized laser printing}, volume={34}, ISSN={["1520-8559"]}, DOI={10.1116/1.4947011}, abstractNote={A facile ultraviolet assisted metalized laser printing technique is demonstrated through the ability to control selective photodeposition of silver on flexible substrates after atomic layer deposition pretreatment with zinc oxide and titania. The photodeposition of noble metals such as silver onto high surface area, polymer supported semiconductor metal oxides exhibits a new route for nanoparticle surface modification of photoactive enhanced substrates. Photodeposited silver is subsequently characterized using low voltage secondary electron microscopy, x-ray diffraction, and time of flight secondary ion mass spectroscopy. At the nanoscale, the formation of specific morphologies, flake and particle, is highlighted after silver is photodeposited on zinc oxide and titania coated substrates, respectively. The results indicate that the morphology and composition of the silver after photodeposition has a strong dependency on the morphology, crystallinity, and impurity content of the underlying semiconductor oxide. At the macroscale, this work demonstrates how the nanoscale features rapidly coalesce into a printed pattern through the use of masks or an X-Y gantry stage with virtually unlimited design control.}, number={3}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Halbur, Jonathan C. and Padbury, Richard P. and Jur, Jesse S.}, year={2016}, month={May} } @article{stano_faraji_hodges_yildiz_wells_akyildiz_zhao_jur_bradford_2016, title={Ultralight Interconnected Metal Oxide Nanotube Networks}, volume={12}, ISSN={["1613-6829"]}, DOI={10.1002/smll.201503267}, abstractNote={Record-breaking ultralow density aluminum oxide structures are prepared using a novel templating technique. The alumina structures are unique in that they are comprised by highly aligned and interconnected nanotubes yielding anisotropic behavior. Large-scale network structures with complex form-factors can easily be made using this technique. The application of the low density networks as humidity sensing materials as well as thermal insulation is demonstrated.}, number={18}, journal={SMALL}, author={Stano, Kelly L. and Faraji, Shaghayegh and Hodges, Ryan and Yildiz, Ozkan and Wells, Brian and Akyildiz, Halil I. and Zhao, Junjie and Jur, Jesse and Bradford, Philip D.}, year={2016}, month={May}, pages={2432–2438} } @article{stano_faraji_hodges_yildiz_wells_akyildiz_zhao_jur_bradford_2016, title={Ultralight Materials: Ultralight Interconnected Metal Oxide Nanotube Networks (Small 18/2016)}, volume={12}, ISSN={1613-6810}, url={http://dx.doi.org/10.1002/SMLL.201670090}, DOI={10.1002/SMLL.201670090}, abstractNote={On page 2432, a novel templating process for the creation of ultralow density metal oxide nanostructures is demonstrated by P. D. Bradford, and co-workers. The alumina structures are unique in that they are comprised of highly aligned and interconnected nanotubes yielding anisotropic behavior. Large-scale network structures with complex form-factors can easily be made using this technique. Application of the low density networks as humidity sensing materials as well as thermal insulation is demonstrated.}, number={18}, journal={Small}, publisher={Wiley}, author={Stano, Kelly L. and Faraji, Shaghayegh and Hodges, Ryan and Yildiz, Ozkan and Wells, Brian and Akyildiz, Halil I. and Zhao, Junjie and Jur, Jesse and Bradford, Philip D.}, year={2016}, month={May}, pages={2387–2387} } @article{akyildiz_mousa_jur_2015, title={Atmospheric pressure synthesis of photoluminescent hybrid materials by sequential organometallic vapor infiltration into polyethylene terephthalate fibers}, volume={117}, ISSN={["1089-7550"]}, DOI={10.1063/1.4906406}, abstractNote={Exposing a polymer to sequential organometallic vapor infiltration (SVI) under low pressure conditions can significantly modify the polymer's chemical, mechanical, and optical properties. We demonstrate that SVI of trimethylaluminum into polyethylene terephthalate (PET) can also proceed readily at atmospheric pressure, and at 60 °C the extent of reaction determined by mass uptake is independent of pressure between 2.5 Torr and 760 Torr. At 120 °C, however, the mass gain is 50% larger at 2.5 Torr relative to that at 760 Torr, indicating that the precursor diffusion in the chamber and fiber matrix decreases at higher source pressure. Mass gain decreases, in general, as the SVI process temperature increases both at 2.5 Torr and 760 Torr attributed to the faster reaction kinetics forming a barrier layer, which prevents further diffusion of the reactive species. The resulting PET/Al-Ox product shows high photoluminescence compared to untreated fibers. A physical mask on the polymer during infiltration at 760 Torr is replicated in the underlying polymer, producing an image in the polymer that is visible under UV illumination. Because of the reduced precursor diffusivity during exposure at 760 Torr, the image shows improved resolution compared to SVI performed under typical 2.5 Torr conditions.}, number={4}, journal={JOURNAL OF APPLIED PHYSICS}, author={Akyildiz, Halil I. and Mousa, Moataz Bellah M. and Jur, Jesse S.}, year={2015}, month={Jan} } @article{marcott_lo_dillon_akyildiz_jur_2015, title={Depth profiling trimethylaluminum-modified PET fibers by nanoscale infrared spectroscopy}, volume={47}, number={2}, journal={American Laboratory}, author={Marcott, C. and Lo, M. and Dillon, E. and Akyildiz, H. I. and Jur, J. S.}, year={2015}, pages={12–14} } @article{misra_bozkurt_calhoun_jackson_jur_lach_lee_muth_oralkan_oeztuerk_et al._2015, title={Flexible Technologies for Self-Powered Wearable Health and Environmental Sensing}, volume={103}, ISSN={["1558-2256"]}, DOI={10.1109/jproc.2015.2412493}, abstractNote={This article provides the latest advances from the NSF Advanced Self-powered Systems of Integrated sensors and Technologies (ASSIST) center. The work in the center addresses the key challenges in wearable health and environmental systems by exploring technologies that enable ultra-long battery lifetime, user comfort and wearability, robust medically validated sensor data with value added from multimodal sensing, and access to open architecture data streams. The vison of the ASSIST center is to use nanotechnology to build miniature, self-powered, wearable, and wireless sensing devices that can enable monitoring of personal health and personal environmental exposure and enable correlation of multimodal sensors. These devices can empower patients and doctors to transition from managing illness to managing wellness and create a paradigm shift in improving healthcare outcomes. This article presents the latest advances in high-efficiency nanostructured energy harvesters and storage capacitors, new sensing modalities that consume less power, low power computation, and communication strategies, and novel flexible materials that provide form, function, and comfort. These technologies span a spatial scale ranging from underlying materials at the nanoscale to body worn structures, and the challenge is to integrate them into a unified device designed to revolutionize wearable health applications.}, number={4}, journal={PROCEEDINGS OF THE IEEE}, author={Misra, Veena and Bozkurt, Alper and Calhoun, Benton and Jackson, Thomas N. and Jur, Jesse S. and Lach, John and Lee, Bongmook and Muth, John and Oralkan, Oemer and Oeztuerk, Mehmet and et al.}, year={2015}, month={Apr}, pages={665–681} } @article{yildiz_stano_faraji_stone_willis_zhang_jur_bradford_2015, title={High performance carbon nanotube - polymer nanofiber hybrid fabrics}, volume={7}, ISSN={["2040-3372"]}, url={https://publons.com/publon/26924675/}, DOI={10.1039/c5nr02732b}, abstractNote={A novel hybridization process combining carbon nanotube sheet drawing and electrospinning is a versatile way to produce multifunctional, binder free fabrics which contain ultra high aspect ratio carbon nanotubes intermingled with polymer nanofibers.}, number={40}, journal={NANOSCALE}, publisher={Royal Society of Chemistry (RSC)}, author={Yildiz, Ozkan and Stano, Kelly and Faraji, Shaghayegh and Stone, Corinne and Willis, Colin and Zhang, Xiangwu and Jur, Jesse S. and Bradford, Philip D.}, year={2015}, pages={16744–16754} } @article{farahbakhsh_roodposhti_ayoub_venditti_jur_2015, title={Melt extrusion of polyethylene nanocomposites reinforced with nanofibrillated cellulose from cotton and wood sources}, volume={132}, ISSN={0021-8995}, url={http://dx.doi.org/10.1002/app.41857}, DOI={10.1002/app.41857}, abstractNote={ABSTRACT}, number={17}, journal={Journal of Applied Polymer Science}, publisher={Wiley}, author={Farahbakhsh, Nasim and Roodposhti, Peiman Shahbeigi and Ayoub, Ali and Venditti, Richard A. and Jur, Jesse S.}, year={2015}, month={Jan} } @article{akyildiz_jur_2015, title={Organometallic exposure dependence on organic-inorganic hybrid material formation in polyethylene terephthalate and polyamide 6 polymer fibers}, volume={33}, ISSN={["1520-8559"]}, DOI={10.1116/1.4907563}, abstractNote={The effect of exposure conditions and surface area on hybrid material formation during sequential vapor infiltrations of trimethylaluminum (TMA) into polyamide 6 (PA6) and polyethylene terephthalate (PET) fibers is investigated. Mass gain of the fabric samples after infiltration was examined to elucidate the reaction extent with increasing number of sequential TMA single exposures, defined as the times for a TMA dose and a hold period. An interdependent relationship between dosing time and holding time on the hybrid material formation is observed for TMA exposure PET, exhibited as a linear trend between the mass gain and total exposure (dose time × hold time × number of sequential exposures). Deviation from this linear relationship is only observed under very long dose or hold times. In comparison, amount of hybrid material formed during sequential exposures to PA6 fibers is found to be highly dependent on amount of TMA dosed. Increasing the surface area of the fiber by altering its cross-sectional dimension is shown to have little on the reaction behavior but does allow for improved diffusion of the TMA into the fiber. This work allows for the projection of exposure parameters necessary for future high-throughput hybrid modifications to polymer materials.}, number={2}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Akyildiz, Halil I. and Jur, Jesse S.}, year={2015}, month={Mar} } @article{padbury_jur_2015, title={Systematic study of trimethyl aluminum infiltration in polyethylene terephthalate and its effect on the mechanical properties of polyethylene terephthalate fibers}, volume={33}, ISSN={["1520-8559"]}, DOI={10.1116/1.4898435}, abstractNote={Hybrid organic–inorganic materials are of increasing interest in the development of novel materials that unite characteristic properties of both organic and inorganic constituents. This work provides a mechanistic understanding of the processing space necessary to utilize hybrid modifications to produce advanced high strength fibrous and textile materials. The infiltration of organometallic precursors into fiber forming polymers and the subsequent formation of a hybrid material interface is detailed. To explore this in more detail, in-situ quartz crystal microgravimetry is employed to investigate the infiltration of trimethyl aluminum (TMA) into polyethylene terephthalate polymer films. Specifically, films with varied crystallinities are explored demonstrating that an increase in crystallinity results in a decrease in mass uptake of trimethyl aluminum. Subsequently, the authors highlight the structure–property relationships between modified and unmodified fibers infiltrated with TMA. For the first time, increases in peak load and elongation is observed by facile exposure to organometallic vapors. The combined peak load and elongation increase is an exciting outcome typically not observed in synthetic fibers.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Padbury, Richard P. and Jur, Jesse S.}, year={2015}, month={Jan} } @article{padbury_halbur_krommenhoek_tracy_jur_2015, title={Thermal Stability of Gold Nanoparticles Embedded within Metal Oxide Frameworks Fabricated by Hybrid Modifications onto Sacrificial Textile Templates}, volume={31}, ISSN={0743-7463 1520-5827}, url={http://dx.doi.org/10.1021/LA504094G}, DOI={10.1021/LA504094G}, abstractNote={The stability and spatial separation of nanoparticles (NP's) is essential for employing their advantageous nanoscale properties. This work demonstrates the entrapment of gold NP's embedded in a porous inorganic matrix. Initially, gold NP's are decorated on fibrous nylon-6, which is used as an inexpensive sacrificial template. This is followed by inorganic modification using a novel single exposure cycle vapor phase technique resulting in distributed NP's embedded within a hybrid organic-inorganic matrix. The processing is extended to the synthesis of porous nanoflakes after calcination of the modified nylon-6 yielding a porous metal oxide framework surrounding the disconnected NP's with a surface area of 250 m(2)/g. A unique feature of this work is the use of a transmission electron microscope (TEM) equipped with an in situ annealing sample holder. The apparatus affords the opportunity to explore the underlying nanoscopic stability of NP's embedded in these frameworks in a single step. TEM analysis indicates thermal stability up to 670 °C and agglomeration characteristics thereafter. The vapor phase processes developed in this work will facilitate new complex NP/oxide materials useful for catalytic platforms.}, number={3}, journal={Langmuir}, publisher={American Chemical Society (ACS)}, author={Padbury, Richard P. and Halbur, Jonathan C. and Krommenhoek, Peter J. and Tracy, Joseph B. and Jur, Jesse S.}, year={2015}, month={Jan}, pages={1135–1141} } @inproceedings{dieffenderfer_goodell_bent_beppler_jayakumar_yokus_jur_bozkurt_peden_2015, title={Wearable wireless sensors for chronic respiratory disease monitoring}, DOI={10.1109/bsn.2015.7299411}, abstractNote={We present a wearable sensor system consisting of a wristband and chest patch to enable the correlation of individual environmental exposure to health response for understanding impacts of ozone on chronic asthma conditions. The wrist worn device measures ambient ozone concentration, heart rate via plethysmography (PPG), three-axis acceleration, ambient temperature, and ambient relative humidity. The chest patch measures heart rate via electrocardiography (ECG) and PPG, respiratory rate via PPG, wheezing via a microphone, and three-axis acceleration. The data from each sensor is continually streamed to a peripheral data aggregation device, and is subsequently transferred to a dedicated server for cloud storage. The current generation of the system uses only commercially-off-the-shelf (COTS) components where the entire electronic structure of the wristband has dimensions of 3.1×4.1×1.2 cm3 while the chest patch electronics has a dimensions of 3.3×4.4×1.2 cm3. The power consumptions of the wristband and chest patch are 78 mW and 33 mW respectively where using a 400 mAh lithium polymer battery would operate the wristband for around 15 hours and the chest patch for around 36 hours.}, booktitle={2015 IEEE 12th International Conference on Wearable and Implantable Body Sensor Networks (BSN)}, author={Dieffenderfer, J. P. and Goodell, H. and Bent, B. and Beppler, E. and Jayakumar, R. and Yokus, M. and Jur, J. S. and Bozkurt, A. and Peden, D.}, year={2015} } @article{padbury_jur_2014, title={Comparison of precursor infiltration into polymer thin films via atomic layer deposition and sequential vapor infiltration using in-situ quartz crystal microgravimetry}, volume={32}, ISSN={["1520-8559"]}, DOI={10.1116/1.4882654}, abstractNote={Previous research exploring inorganic materials nucleation behavior on polymers via atomic layer deposition indicates the formation of hybrid organic–inorganic materials that form within the subsurface of the polymer. This has inspired adaptations to the process, such as sequential vapor infiltration, which enhances the diffusion of organometallic precursors into the subsurface of the polymer to promote the formation of a hybrid organic–inorganic coating. This work highlights the fundamental difference in mass uptake behavior between atomic layer deposition and sequential vapor infiltration using in-situ methods. In particular, in-situ quartz crystal microgravimetry is used to compare the mass uptake behavior of trimethyl aluminum in poly(butylene terephthalate) and polyamide-6 polymer thin films. The importance of trimethyl aluminum diffusion into the polymer subsurface and the subsequent chemical reactions with polymer functional groups are discussed.}, number={4}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Padbury, Richard P. and Jur, Jesse S.}, year={2014}, month={Jul} } @article{stano_carroll_padbury_mccord_jur_bradford_2014, title={Conformal Atomic Layer Deposition of Alumina on Millimeter Tall, Vertically-Aligned Carbon Nanotube Arrays}, volume={6}, ISSN={["1944-8244"]}, DOI={10.1021/am505107s}, abstractNote={Atomic layer deposition (ALD) can be used to coat high aspect ratio and high surface area substrates with conformal and precisely controlled thin films. Vertically aligned arrays of multiwalled carbon nanotubes (MWCNTs) with lengths up to 1.5 mm were conformally coated with alumina from base to tip. The nucleation and growth behaviors of Al2O3 ALD precursors on the MWCNTs were studied as a function of CNT surface chemistry. CNT surfaces were modified through a series of post-treatments including pyrolytic carbon deposition, high temperature thermal annealing, and oxygen plasma functionalization. Conformal coatings were achieved where post-treatments resulted in increased defect density as well as the extent of functionalization, as characterized by X-ray photoelectron spectroscopy and Raman spectroscopy. Using thermogravimetric analysis, it was determined that MWCNTs treated with pyrolytic carbon and plasma functionalization prior to ALD coating were more stable to thermal oxidation than pristine ALD coated samples. Functionalized and ALD coated arrays had a compressive modulus more than two times higher than a pristine array coated for the same number of cycles. Cross-sectional energy dispersive X-ray spectroscopy confirmed that Al2O3 could be uniformly deposited through the entire thickness of the vertically aligned MWCNT array by manipulating sample orientation and mounting techniques. Following the ALD coating, the MWCNT arrays demonstrated hydrophilic wetting behavior and also exhibited foam-like recovery following compressive strain.}, number={21}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Stano, Kelly L. and Carroll, Murphy and Padbury, Richard and McCord, Marian and Jur, Jesse S. and Bradford, Philip D.}, year={2014}, month={Nov}, pages={19135–19143} } @article{padbury_jur_2014, title={Effect of Polymer Microstructure on the Nucleation Behavior of Alumina via Atomic Layer Deposition}, volume={118}, ISSN={["1932-7455"]}, DOI={10.1021/jp506456y}, abstractNote={Atomic layer deposition is a technique that is able to integrate nanoscale inorganic coatings to organic polymers. Through this process a number of different inorganic coating morphologies are able to form during ALD nucleation on a wide variety of polymers. In this work, we provide a systematic analysis of the ALD nucleation characteristics on polymers that have subtle variations in microstructure, such as, the addition of pendant groups or change in length of the polymer repeat unit. Specifically, in situ quartz crystal microgravimetry is employed to understand the nucleation behavior of alumina ALD in a series of poly n-methacrylate and polyester thin films. The work indicates the effect that a subtle change in polymer microstructure has on the properties of the polymer film. The data indicates that the glass transition temperature of the polymer, as influenced by variations in microstructure, has a significant impact on the absorption/desorption characteristics during TMA/water exposures. Through this...}, number={32}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Padbury, Richard P. and Jur, Jesse S.}, year={2014}, month={Aug}, pages={18805–18813} } @article{akyildiz_lo_dillon_roberts_everitt_jur_2014, title={Formation of novel photoluminescent hybrid materials by sequential vapor infiltration into polyethylene terephthalate fibers}, volume={29}, ISSN={["2044-5326"]}, DOI={10.1557/jmr.2014.333}, abstractNote={Abstract}, number={23}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Akyildiz, Halil I. and Lo, Michael and Dillon, Eoghan and Roberts, Adam T. and Everitt, Henry O. and Jur, Jesse S.}, year={2014}, month={Dec}, pages={2817–2826} } @article{farahbakhsh_venditti_jur_2014, title={Mechanical and thermal investigation of thermoplastic nanocomposite films fabricated using micro- and nano-sized fillers from recycled cotton T-shirts}, volume={21}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-014-0285-4}, number={4}, journal={CELLULOSE}, author={Farahbakhsh, Nasim and Venditti, Richard A. and Jur, Jesse S.}, year={2014}, month={Aug}, pages={2743–2755} } @article{padbury_jur_2014, title={Temperature-Dependent Infiltration of Polymers during Sequential Exposures to Trimethylaluminum}, volume={30}, ISSN={["0743-7463"]}, DOI={10.1021/la501679f}, abstractNote={Atomic layer deposition provides the opportunity to introduce nanoscale inorganic coatings to organic polymers creating coatings of varied compositions of finish with distinctive interfaces. Prior research has shown that ALD materials nucleation on polymers varies in composition and structure based on how the precursor interacts with the polymer chemistry and the process conditions. To study this in more detail, in situ quartz crystal microgravimetry is employed to understand the infiltration and saturation behavior of trimethylaluminum in polyamide-6, poly(acrylic acid), poly(ethylene terephthalate), and poly(methyl methacrylate). Emphasis is placed on understanding reactive vapor diffusion into these polymers as the exposure temperature is varied. Finally, we propose potential growth mechanisms based on the temperature-dependent observations in this work that enables the ability to produce a customized interface for ALD materials growth on polymer substrates.}, number={30}, journal={LANGMUIR}, author={Padbury, Richard P. and Jur, Jesse S.}, year={2014}, month={Aug}, pages={9228–9238} } @article{li_sun_xu_lu_zhang_xue_jur_zhang_2014, title={Tuning electrochemical performance of Si-based anodes for lithium-ion batteries by employing atomic layer deposition alumina coating}, volume={2}, ISSN={["2050-7496"]}, url={https://publons.com/publon/11754001/}, DOI={10.1039/c4ta01562b}, abstractNote={A free-standing, conductive and three-dimensional network of Al2O3-coated Si/C composite nanofibers is fabricated by a single-nozzle electrospinning and atomic layer deposition. The as-obtained Al2O3-coated Si/C composite nanofibers exhibit excellent electrochemical performance for applications as anode materials for lithium-ion batteries.}, number={29}, journal={JOURNAL OF MATERIALS CHEMISTRY A}, publisher={Royal Society of Chemistry (RSC)}, author={Li, Ying and Sun, Yujie and Xu, Guanjie and Lu, Yao and Zhang, Shu and Xue, Leigang and Jur, Jesse S. and Zhang, Xiangwu}, year={2014}, pages={11417–11425} } @article{sweet_jur_parsons_2013, title={Bi-layer Al2O3/ZnO atomic layer deposition for controllable conductive coatings on polypropylene nonwoven fiber mats}, volume={113}, ISSN={["0021-8979"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000319295200047&KeyUID=WOS:000319295200047}, DOI={10.1063/1.4804960}, abstractNote={Electrically conductive zinc oxide coatings are applied to polypropylene nonwoven fiber mats by atomic layer deposition (ALD) at 50–155 °C. A low temperature (50 °C) aluminum oxide ALD base layer on the polypropylene limits diffusion of diethyl zinc into the polypropylene, resulting in ZnO layers with properties similar to those on planar silicon. Effective conductivity of 63 S/cm is achieved for ZnO on Al2O3 coated polypropylene fibers, and the fibers remain conductive for months after coating. Without the Al2O3 precoating, the effective conductivity was much smaller, consistent with precursor diffusion into the polymer and sub-surface ZnO nucleation. Mechanical robustness tests showed that conductive samples bent around a 6 mm radius maintained up to 40% of the pre-bending conductivity. Linkages between electrical conductivity and mechanical performance will help inform materials choice for flexible and porous electronics including textile-based sensors and antennas.}, number={19}, journal={JOURNAL OF APPLIED PHYSICS}, author={Sweet, William J., III and Jur, Jesse S. and Parsons, Gregory N.}, year={2013}, month={May} } @article{halbur_padbury_jur_2013, title={Induced wetting of polytetrafluoroethylene by atomic layer deposition for application of aqueous-based nanoparticle inks}, volume={101}, ISSN={["1873-4979"]}, DOI={10.1016/j.matlet.2013.03.063}, abstractNote={Atomic layer deposition of aluminum oxide is shown to control the surface energy and wetting properties of polytetrafluoroethylene (PTFE) films and membranes. Independent of deposition temperature, gradual and abrupt wetting transitions were observed for PTFE films and membranes, respectively. To assess the enhanced compatibility of treated PTFE substrates with nanoparticle inks, drop casting and inkjet printing of silver nanoparticle solutions are performed and analyzed by optical microscopy and time of flight secondary ion mass spectroscopy. Untreated PTFE substrates showed poor compatibility with the nanoparticle inks, drying in a coffee ring pattern, whereas aluminum oxide treated PTFE substrates exhibited uniform silver nanoparticle distribution after drying.}, journal={MATERIALS LETTERS}, author={Halbur, Jonathan C. and Padbury, Richard P. and Jur, Jesse S.}, year={2013}, month={Jun}, pages={25–28} } @article{sun_padbury_akyildiz_goertz_palmer_jur_2013, title={Influence of Subsurface Hybrid Material Growth on the Mechanical Properties of Atomic Layer Deposited Thin Films on Polymers}, volume={19}, ISSN={["1521-3862"]}, DOI={10.1002/cvde.201207042}, abstractNote={Abstract}, number={4-6}, journal={CHEMICAL VAPOR DEPOSITION}, author={Sun, Yujie and Padbury, Richard P. and Akyildiz, Halil I. and Goertz, Matthew P. and Palmer, Jeremy A. and Jur, Jesse S.}, year={2013}, month={Jun}, pages={134–141} } @misc{parsons_atanasov_dandley_devine_gong_jur_lee_oldham_peng_spagnola_et al._2013, title={Mechanisms and reactions during atomic layer deposition on polymers}, volume={257}, ISSN={["1873-3840"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000327915000012&KeyUID=WOS:000327915000012}, DOI={10.1016/j.ccr.2013.07.001}, abstractNote={There is significant growing interest in atomic layer deposition onto polymers for barrier coatings, nanoscale templates, surface modification layers and other applications. The ability to control the reaction between ALD precursors and polymers opens new opportunities in ALD materials processing. It is well recognized that ALD on many polymers involves subsurface precursor diffusion and reaction which are not encountered during ALD on solid surfaces. This article reviews recent insights into chemical reactions that proceed during ALD on polymers, with particular focus on the common Al2O3 reaction sequence using trimethyl aluminum (TMA) and water. We highlight the role of different polymer reactive groups in film growth, and how the balance between precursor diffusion and reaction can change as deposition proceeds. As a strong Lewis acid, TMA forms adducts with Lewis base sites within the polymer, and the reactions that proceed are determined by the neighboring bond structure. Moreover, the Lewis base sites can be saturated by TMA, producing a self-limiting half-reaction within a three-dimensional polymer, analogous to a self-limiting half-reaction commonly observed during ALD on a solid planar surface.}, number={23-24}, journal={COORDINATION CHEMISTRY REVIEWS}, author={Parsons, Gregory N. and Atanasov, Sarah E. and Dandley, Erinn C. and Devine, Christina K. and Gong, Bo and Jur, Jesse S. and Lee, Kyoungmi and Oldham, Christopher J. and Peng, Qing and Spagnola, Joseph C. and et al.}, year={2013}, month={Dec}, pages={3323–3331} } @article{mousa_oldham_jur_parsons_2012, title={Effect of temperature and gas velocity on growth per cycle during Al2O3 and ZnO atomic layer deposition at atmospheric pressure}, volume={30}, ISSN={["1520-8559"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000298992800055&KeyUID=WOS:000298992800055}, DOI={10.1116/1.3670961}, abstractNote={The growth per cycle as a function of temperature during atomic layer deposition (ALD) of Al2O3 and ZnO at atmospheric pressure follows very closely the trend measured at typical (∼2 Torr) process pressure. However, the overall growth rate is found to be nearly 2 × larger at higher pressure and the magnitude of the growth increase can be adjusted by controlling the gas velocity near the growth surface. The growth increase at high pressure is approximately independent of process temperature at T   150 °C, especially for Al2O3. The relatively high growth/cycle measured at 760 Torr and T < 150 °C suggests that excess physisorbed water remains on the alumina or zinc oxide surface after the water purge step. Increasing the gas velocity in the growth zone reduces the growth rate, consistent with more efficient removal of excess water. To better understand the observed trends, we present analytical expressions for the boundary layer...}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Mousa, Moataz Bellah M. and Oldham, Christopher J. and Jur, Jesse S. and Parsons, Gregory N.}, year={2012}, month={Jan} } @article{lee_jur_kim_parsons_2012, title={Mechanisms for hydrophilic/hydrophobic wetting transitions on cellulose cotton fibers coated using Al2O3 atomic layer deposition}, volume={30}, ISSN={["0734-2101"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000298992800063&KeyUID=WOS:000298992800063}, DOI={10.1116/1.3671942}, abstractNote={This report explores reactions that proceed during the first few cycles of inorganic film atomic layer deposition (ALD) on natural cellulose cotton fibers, and how surface reactions can explain the previously observed transitions in surface wetting upon ALD on cotton fibers. Atomic layer deposition of aluminum oxide and zinc oxide onto natural cotton cellulose produces a transition from hydrophilic to hydrophobic, then from hydrophobic back to hydrophilic, and we describe here the main factors that bring about. Interestingly, we show that air exposure and related adventitious carbon adsorption also affects the subsequent reactions and wetting properties obtained after subsequent ALD cycles. X-ray photoelectron spectroscopy and in situ Fourier transform infrared spectroscopy data indicate Al-(O-C-)3 bonding units form when trimethylaluminum interacts with surface –OH units during the first precursor doses, producing a hydrophobic finish on the cotton that remains for only a few ALD cycles. Also, field-emission scanning electron microscopy results show that some surface roughening may occur in the first few ALD cycles, and the roughening of the hydrophobic-finished surface can also promote an increase in measured hydrophobicity.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A}, author={Lee, Kyoungmi and Jur, Jesse S. and Kim, Do Han and Parsons, Gregory N.}, year={2012}, month={Jan} } @inproceedings{grewal_sweesy_jur_willoughby_2012, title={Moisture vapor barrier properties of biopolymers for packaging materials}, volume={1107}, DOI={10.1021/bk-2012-1107.ch015}, abstractNote={We present a review of current research focused on the use of biopolymers as viable packaging materials. We discuss polysaccharides, proteins, lipids, materials systems comprising edible coatings, and inorganic surface modification processes as they impact moisture barrier permeability properties. We give an overview of the fundamental factors that affect moisture vapor permeability (MVP), provide an overview of barrier properties for typical packaging materials on a common unit basis, and the MVP improvements made with evolving techniques. We explore some challenges and unknowns with surface modifications specific to altering the barrier properties of polymers derived from renewable resources. We provide some of the future directions in our own work to improve materials with inherently poor moisture vapor properties using the insights from this review as a road map.}, booktitle={Functional materials from renewable sources}, author={Grewal, R. and Sweesy, W. and Jur, J. S. and Willoughby, J.}, year={2012}, pages={271–296} } @article{jur_parsons_2012, title={Nanoscale ceramic surface modification of textiles by atomic layer deposition}, volume={91}, number={6}, journal={American Ceramic Society Bulletin}, author={Jur, J. S. and Parsons, G. N.}, year={2012}, pages={24–27} } @article{kim_koo_jur_woodroof_kalanyan_lee_devine_parsons_2012, title={Stable anatase TiO2 coating on quartz fibers by atomic layer deposition for photoactive light-scattering in dye-sensitized solar cells}, volume={4}, ISSN={["2040-3372"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000306324000056&KeyUID=WOS:000306324000056}, DOI={10.1039/c2nr30939d}, abstractNote={Quartz fibers provide a unique high surface-area substrate suitable for conformal coating using atomic layer deposition (ALD), and are compatible with high temperature annealing. This paper shows that the quartz fiber composition stabilizes ALD TiO(2) in the anatase phase through TiO(2)-SiO(2) interface formation, even after annealing at 1050 °C. When integrated into a dye-sensitized solar cell, the TiO(2)-coated quartz fiber mat improves light scattering performance. Results also confirm that annealing at high temperature is necessary for better photoactivity of ALD TiO(2), which highlights the significance of quartz fibers as a substrate. The ALD TiO(2) coating on quartz fibers also boosts dye adsorption and photocurrent response, pushing the overall efficiency of the dye-cells from 6.5 to 7.4%. The mechanisms for improved cell performance are confirmed using wavelength-dependent incident photon to current efficiency and diffuse light scattering results. The combination of ALD and thermal processing on quartz fibers may enable other device structures for energy conversion and catalytic reaction applications.}, number={15}, journal={NANOSCALE}, author={Kim, Do Han and Koo, Hyung-Jun and Jur, Jesse S. and Woodroof, Mariah and Kalanyan, Berc and Lee, Kyoungmi and Devine, Christina K. and Parsons, Gregory N.}, year={2012}, pages={4731–4738} } @article{akyildiz_padbury_parsons_jur_2012, title={Temperature and Exposure Dependence of Hybrid Organic-Inorganic Layer Formation by Sequential Vapor Infiltration into Polymer Fibers}, volume={28}, ISSN={["0743-7463"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000310664300032&KeyUID=WOS:000310664300032}, DOI={10.1021/la302991c}, abstractNote={The characteristic processing behavior for growth of a conformal nanoscale hybrid organic-inorganic modification to polyamide 6 (PA6) by sequential vapor infiltration (SVI) is demonstrated. The SVI process is a materials growth technique by which exposure of organometallic vapors to a polymeric material promotes the formation of a hybrid organic-inorganic modification at the near surface region of the polymer. This work investigates the SVI exposure temperature and cycling times of sequential exposures of trimethylaluminum (TMA) on PA6 fiber mats. The result of TMA exposure is the preferential subsurface organic-inorganic growth by diffusion into the polymer and reaction with the carbonyl in PA6. Mass gain, infrared spectroscopy, and transmission electron microscopy analysis indicate enhanced materials growth and uniformity at lower processing temperatures. The inverse relationship between mass gain and exposure temperature is explained by the formation of a hybrid layer that prevents the diffusion of TMA into the polymer to react with the PA6 upon subsequent exposure cycles. As few as 10 SVI exposure cycles are observed to saturate the growth, yielding a modified thickness of ∼75 nm and mass increase of ∼14 wt %. Removal of the inherent PA6 moisture content reduces the mass gain by ∼4 wt % at low temperature exposures. The ability to understand the characteristic growth process is critical for the development of the hybrid materials fabrication and modification techniques.}, number={44}, journal={LANGMUIR}, author={Akyildiz, Halil I. and Padbury, Richard P. and Parsons, Gregory N. and Jur, Jesse S.}, year={2012}, month={Nov}, pages={15697–15704} } @article{jur_parsons_2011, title={Atomic Layer Deposition of Al2O3 and ZnO at Atmospheric Pressure in a Flow Tube Reactor}, volume={3}, ISSN={["1944-8252"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000287639400029&KeyUID=WOS:000287639400029}, DOI={10.1021/am100940g}, abstractNote={Improving nanoscale thin film deposition techniques such as atomic layer deposition (ALD) to permit operation at ambient pressure is important for high-throughput roll-to-roll processing of emerging flexible substrates, including polymer sheets and textiles. We present and investigate a novel reactor design for inorganic materials growth by ALD at atmospheric pressure. The reactor uses a custom "pressure boost" approach for delivery of low vapor pressure ALD precursors that controls precursor dose independent of reactor pressure. Analysis of continuum gas flow in the reactor shows key relations among reactor pressure, inert gas flow rate, and species diffusion that define conditions needed to efficiently remove product and adsorbed reactive species from the substrate surface during the inert gas purge cycle. Experimental results, including in situ quartz crystal microbalance (QCM) characterization and film thickness measurements for deposition of ZnO and Al(2)O(3) are presented and analyzed as a function of pressure and gas flow rates at 100 °C. At atmospheric pressure and high gas flow, ZnO deposition can proceed at the same mass uptake and growth rate as observed during more typical low pressure ALD. However, under the same high pressure and flow conditions the mass uptake and growth rate for Al(2)O(3) is a factor of ∼1.5-2 larger than at low pressure. Under these conditions, Al(2)O(3) growth at atmospheric pressure in a "flow-through" geometry on complex high surface area textile materials is sufficiently uniform to yield functional uniform coatings.}, number={2}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Jur, Jesse S. and Parsons, Gregory N.}, year={2011}, month={Feb}, pages={299–308} } @article{jur_sweet_oldham_parsons_2011, title={Atomic Layer Deposition of Conductive Coatings on Cotton, Paper, and Synthetic Fibers: Conductivity Analysis and Functional Chemical Sensing Using “All-Fiber” Capacitors}, volume={21}, ISSN={1616-301X}, url={http://dx.doi.org/10.1002/adfm.201001756}, DOI={10.1002/adfm.201001756}, abstractNote={Abstract}, number={11}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Jur, Jesse. S. and Sweet, William J., III and Oldham, Christopher J. and Parsons, Gregory N.}, year={2011}, month={Mar}, pages={1993–2002} } @article{jur_sweet_oldham_parsons_2011, title={Electronic Textiles: Atomic Layer Deposition of Conductive Coatings on Cotton, Paper, and Synthetic Fibers: Conductivity Analysis and Functional Chemical Sensing Using “All-Fiber” Capacitors (Adv. Funct. Mater. 11/2011)}, volume={21}, ISSN={1616-301X}, url={http://dx.doi.org/10.1002/adfm.201190035}, DOI={10.1002/adfm.201190035}, abstractNote={Electronic functionalization of complex fiber systems is important for new applications in energy systems and electronic textiles. The cover image shows a natural fibrous material with and without conductive coating. Atomic layer deposition (ALD) of conductive coatings on natural and synthetic fibrous materials show high conductivity, and the values scale as expected with film thickness and bulk-material conductance. On page 1993, Jesse S. Jur and co-workers present an all-fiber-based capacitor formed by ALD on textiles that shows good sensing performance in several liquid media.}, number={11}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Jur, Jesse. S. and Sweet, William J., III and Oldham, Christopher J. and Parsons, Gregory N.}, year={2011}, month={May}, pages={1948–1948} } @article{oldham_gong_spagnola_jur_senecal_godfrey_parsons_2011, title={Encapsulation and Chemical Resistance of Electrospun Nylon Nanofibers Coated Using Integrated Atomic and Molecular Layer Deposition}, volume={158}, ISSN={["1945-7111"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000293175600039&KeyUID=WOS:000293175600039}, DOI={10.1149/1.3609046}, abstractNote={Nanofibers formed by electrospinning provide very large surface areas which can enhance material performance in filtration and product separation. In this work, we explore atomic layer deposition (ALD) as a means to coat and protect electrospun nylon-6 nanofibers. Exposing nylon to trimethyl aluminum (TMA) during ALD of aluminum oxide results in significant fiber degradation. Protecting fibers with a bilayer of ALD ZnO and an organic-inorganic hybrid polymer by molecular layer deposition maintains the shape of the original nanofibers, but chemical modification is still detected. These coating processes may help enable nanofibers with stable physical properties under chemical exposure.}, number={9}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Oldham, Christopher J. and Gong, Bo and Spagnola, Joseph C. and Jur, Jesse S. and Senecal, Kris J. and Godfrey, Thomas A. and Parsons, Gregory N.}, year={2011}, pages={D549–D556} } @article{jur_wheeler_lichtenwalner_maria_johnson_2011, title={Epitaxial growth of lanthanide oxides La2O3 and Sc2O3 on GaN}, volume={98}, ISSN={["0003-6951"]}, DOI={10.1063/1.3541883}, abstractNote={Deposition of lanthanide oxides on GaN is investigated as a means to produce stable dielectric with good interface quality. Epitaxial growth of cubic ⟨111⟩-oriented Sc2O3 is observed on GaN [0001] with a lattice mismatch of 7.2%, whereas La2O3 growth, with a lattice mismatch of ∼21%, results in a mixed phase epitaxial film comprised of the bixbyite and hexagonal allotropes. Substantial roughening accompanies this mixed phase film. By inserting a thin Sc2O3 interfacial layer between La2O3 and GaN and a Sc2O3 capping layer, the crystal quality of the predominantly La2O3 layer is improved and the stack is stabilized against hydroxide formation under ambient conditions.}, number={4}, journal={APPLIED PHYSICS LETTERS}, author={Jur, Jesse S. and Wheeler, Virginia D. and Lichtenwalner, Daniel J. and Maria, Jon-Paul and Johnson, Mark A. L.}, year={2011}, month={Jan} } @article{devine_oldham_jur_gong_parsons_2011, title={Fiber Containment for Improved Laboratory Handling and Uniform Nanocoating of Milligram Quantities of Carbon Nanotubes by Atomic Layer Deposition}, volume={27}, ISSN={0743-7463 1520-5827}, url={http://dx.doi.org/10.1021/la202677u}, DOI={10.1021/la202677u}, abstractNote={The presence of nanostructured materials in the workplace is bringing attention to the importance of safe practices for nanomaterial handling. We explored novel fiber containment methods to improve the handling of carbon nanotube (CNT) powders in the laboratory while simultaneously allowing highly uniform and controlled atomic layer deposition (ALD) coatings on the nanotubes, down to less than 4 nm on some CNT materials. Moreover, the procedure yields uniform coatings on milligram quantities of nanotubes using a conventional viscous flow reactor system, circumventing the need for specialized fluidized bed or rotary ALD reactors for laboratory-scale studies. We explored both fiber bundles and fiber baskets as possible containment methods and conclude that the baskets are more suitable for coating studies. An extended precursor and reactant dose and soak periods allowed the gases to diffuse through the fiber containment, and the ALD coating thickness scaled linearly with the number of ALD cycles. The extended dose period produced thicker coatings compared to typical doses on CNT controls not encased in the fibers, suggesting some effects due to the extended reactant dose. Film growth was compared on a range of single-walled NTs, double-walled NTs, and acid-functionalized multiwalled NTs, and we found that ultrathin coatings were most readily controlled on the multiwalled NTs.}, number={23}, journal={Langmuir}, publisher={American Chemical Society (ACS)}, author={Devine, Christina K. and Oldham, Christopher J. and Jur, Jesse S. and Gong, Bo and Parsons, Gregory N.}, year={2011}, month={Dec}, pages={14497–14507} } @article{gong_peng_jur_devine_lee_parsons_2011, title={Sequential Vapor Infiltration of Metal Oxides into Sacrificial Polyester Fibers: Shape Replication and Controlled Porosity of Microporous/Mesoporous Oxide Monoliths}, volume={23}, ISSN={0897-4756 1520-5002}, url={http://dx.doi.org/10.1021/cm200694w}, DOI={10.1021/cm200694w}, abstractNote={The preparation of microporous and mesoporous metal oxide materials continues to attract considerable attention, because of their possible use in chemical separations, catalyst support, chemical sensors, optical and electronic devices, energy storage, and solar cells. While many methods are known for the synthesis of porous materials, researchers continue to seek new methods to control pore size distribution and macroscale morphology. In this work, we show that sequential vapor infiltration (SVI) can yield shape-controlled micro/mesoporous materials with tunable pore size, using polyesters as a sacrificial template. The reaction proceeds by exposing polymer fiber templates to a controlled sequence of metal organic and co-reactant vapor exposure cycles in an atomic layer deposition (ALD) reactor. The precursors infuse sequentially and thereby distribute and react uniformly within the polymer, to yield an organic–inorganic hybrid material that retains the physical dimensions of the original polymer template...}, number={15}, journal={Chemistry of Materials}, publisher={American Chemical Society (ACS)}, author={Gong, Bo and Peng, Qing and Jur, Jesse S. and Devine, Christina K. and Lee, Kyoungmi and Parsons, Gregory N.}, year={2011}, month={Aug}, pages={3476–3485} } @article{hyde_scarel_spagnola_peng_lee_gong_roberts_roth_hanson_devine_et al._2010, title={Atomic Layer Deposition and Abrupt Wetting Transitions on Nonwoven Polypropylene and Woven Cotton Fabrics}, volume={26}, ISSN={["0743-7463"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000274342200056&KeyUID=WOS:000274342200056}, DOI={10.1021/la902830d}, abstractNote={Atomic layer deposition (ALD) of aluminum oxide on nonwoven polypropylene and woven cotton fabric materials can be used to transform and control fiber surface wetting properties. Infrared analysis shows that ALD can produce a uniform coating throughout the nonwoven polypropylene fiber matrix, and the amount of coating can be controlled by the number of ALD cycles. Upon coating by ALD aluminum oxide, nonwetting hydrophobic polypropylene fibers transition to either a metastable hydrophobic or a fully wetting hydrophilic state, consistent with well-known Cassie-Baxter and Wenzel models of surface wetting of roughened surfaces. The observed nonwetting/wetting transition depends on ALD process variables such as the number of ALD coating cycles and deposition temperature. Cotton fabrics coated with ALD aluminum oxide at moderate temperatures were also observed to transition from a natural wetting state to a metastable hydrophobic state and back to wetting depending on the number of ALD cycles. The transitions on cotton appear to be less sensitive to deposition temperature. The results provide insight into the effect of ALD film growth mechanisms on hydrophobic and hydrophilic polymers and fibrous structures. The ability to adjust and control surface energy, surface reactivity, and wettability of polymer and natural fiber systems using atomic layer deposition may enable a wide range of new applications for functional fiber-based systems.}, number={4}, journal={LANGMUIR}, author={Hyde, G. Kevin and Scarel, Giovanna and Spagnola, Joseph C. and Peng, Qing and Lee, Kyoungmi and Gong, Bo and Roberts, Kim G. and Roth, Kelly M. and Hanson, Christopher A. and Devine, Christina K. and et al.}, year={2010}, month={Feb}, pages={2550–2558} } @article{spagnola_gong_arvidson_jur_khan_parsons_2010, title={Surface and sub-surface reactions during low temperature aluminium oxide atomic layer deposition on fiber-forming polymers}, volume={20}, ISSN={["0959-9428"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000277563800026&KeyUID=WOS:000277563800026}, DOI={10.1039/c0jm00355g}, abstractNote={Fundamental reaction processes between vapor-phase chemical precursors and high molecular weight polymers are important for polymer coating, encapsulation and surface modification. Using trimethylaluminium and water in an atomic layer deposition (ALD) exposure sequence, reactions between vapor-phase trimethylaluminium and common polymers with different substituents are quantified using in situ infrared transmission analysis. Exposing polypropylene to trimethylaluminium results in reactant uptake with minimal precursor/polymer reaction, but the precursor/water ALD sequence leads to subsurface alumina nucleation. A similar treatment to polyvinyl alcohol and polyamide-6 results in rapid precursor diffusion and significant reaction observed by IR, and the extent of reaction is consistent with results from in situ quartz crystal microgravimetry and transmission electron microscopy. Reacting trimethylaluminium with polyamide-6 leads to methyl group insertion into the amide carbonyl group and interaction with the hydrogen-bonded amine units. Multiple ALD reaction cycles produce film coatings on all polymers studied, but the coating structure depends strongly on the starting polymer composition. For the weakly interacting polypropylene, cross-sectional transmission electron microscopy demonstrates enhanced sub-surface growth at 90 °C as compared to that at 60 °C, while images of coated polyamide-6 fibers showed that growth is not strongly temperature dependent in that range. Micrograph images of polyamide-6 samples exposed to extended TMA doses revealed significant modification of the fiber surface region, demonstrating that the precursor could diffuse and react to depths in excess of 100 nm into the surface of the polymer at 90 °C. Improved understanding of specific precursor/polymer reaction pathways can be important to optimize the performance of conformal inorganic thin film coatings on polymers.}, number={20}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Spagnola, Joseph C. and Gong, Bo and Arvidson, Sara A. and Jur, Jesse S. and Khan, Saad A. and Parsons, Gregory N.}, year={2010}, pages={4213–4222} } @article{jur_spagnola_lee_gong_peng_parsons_2010, title={Temperature-Dependent Subsurface Growth during Atomic Layer Deposition on Polypropylene and Cellulose Fibers}, volume={26}, ISSN={["0743-7463"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000277928100078&KeyUID=WOS:000277928100078}, DOI={10.1021/la904604z}, abstractNote={Nucleation and subsequent growth of aluminum oxide by atomic layer deposition (ALD) on polypropylene fiber substrates is strongly dependent on processing temperature and polymer backbone structure. Deposition on cellulose cotton, which contains ample hydroxyl sites for ALD nucleation and growth on the polymer backbone, readily produces a uniform and conformal coating. However, similar ALD processing on polypropylene, which contains no readily available active sites for growth initiation, results in a graded and intermixed polymer/inorganic interface layer. The structure of the polymer/inorganic layer depends strongly on the process temperature, where lower temperature (60 degrees C) produced a more abrupt transition. Cross-sectional transmission electron microscopy images of polypropylene fibers coated at higher temperature (90 degrees C) show that non-coalesced particles form in the near-surface region of the polymer, and the particles grow in size and coalesce into a film as the number of ALD cycles increases. Quartz crystal microbalance analysis on polypropylene films confirms enhanced mass uptake at higher processing temperatures, and X-ray photoelectron spectroscopy data also confirm heterogeneous mixing between the aluminum oxide and the polypropylene during deposition at higher temperatures. The strong temperature dependence of film nucleation and subsurface growth is ascribed to a relatively large increase in bulk species diffusivity that occurs upon the temperature-driven free volume expansion of the polypropylene. These results provide helpful insight into mechanisms for controlled organic/inorganic thin film and fiber materials integration.}, number={11}, journal={LANGMUIR}, author={Jur, Jesse S. and Spagnola, Joseph C. and Lee, Kyoungmi and Gong, Bo and Peng, Qing and Parsons, Gregory N.}, year={2010}, month={Jun}, pages={8239–8244} } @article{sethuraman_khan_jur_haug_weidner_2009, title={Measuring oxygen, carbon monoxide and hydrogen sulfide diffusion coefficient and solubility in Nafion membranes}, volume={54}, ISSN={0013-4686}, url={http://dx.doi.org/10.1016/j.electacta.2009.06.068}, DOI={10.1016/j.electacta.2009.06.068}, abstractNote={A Devanathan–Stachurski type diffusion cell made from a fuel cell assembly is designed to evaluate the gas transport properties of a proton exchange membrane as a function of cell temperature and gas pressure. Data obtained on this cell using the electrochemical monitoring technique (EMT) is used to estimate solubility and diffusion coefficient of oxygen (O2), carbon monoxide (CO) and hydrogen sulfide (H2S) in Nafion membranes. Membrane swelling and reverse-gas diffusion due to water flux are accounted for in the parameter estimation procedure. Permeability of all three gases was found to increase with temperature. The estimated activation energies for O2, CO and H2S diffusion in Nafion 112 are 12.58, 20 and 8.85 kJ mol−1, respectively. The estimated enthalpies of mixing for O2, CO and H2S in Nafion 112 are 5.88, 3.74 and 7.61 kJ mol−1, respectively. An extensive comparison of transport properties estimated in this study to those reported in the literature suggests good agreement. Oxygen permeability in Nafion 117 was measured as a function of gas pressures between 1 and 3 atm. Oxygen diffusion coefficient in Nafion 117 is invariant with pressure and the solubility increases with pressure and obeys Henry's law. The estimated Henry's constant is 3.5 × 103 atm.}, number={27}, journal={Electrochimica Acta}, publisher={Elsevier BV}, author={Sethuraman, Vijay A. and Khan, Saahir and Jur, Jesse S. and Haug, Andrew T. and Weidner, John W.}, year={2009}, month={Nov}, pages={6850–6860} } @article{kirsch_sivasubramani_huang_young_quevedo-lopez_wen_alshareef_choi_park_freeman_et al._2008, title={Dipole model explaining high-k/metal gate field effect transistor threshold voltage tuning}, volume={92}, ISSN={["1077-3118"]}, DOI={10.1063/1.2890056}, abstractNote={An interface dipole model explaining threshold voltage (Vt) tuning in HfSiON gated n-channel field effect transistors (nFETs) is proposed. Vt tuning depends on rare earth (RE) type and diffusion in Si∕SiOx∕HfSiON∕REOx/metal gated nFETs as follows: Sr