@article{erlenbach_mondal_ma_neumann_ma_holbery_dickey_2023, title={Flexible-to-Stretchable Mechanical and Electrical Interconnects}, volume={1}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.2c14260}, DOI={10.1021/acsami.2c14260}, abstractNote={Stretchable electronic devices that maintain electrical function when subjected to stress or strain are useful for enabling new applications for electronics, such as wearable devices, human-machine interfaces, and components for soft robotics. Powering and communicating with these devices is a challenge. NFC (near-field communication) coils solve this challenge but only work efficiently when they are in close proximity to the device. Alternatively, electrical signals and power can arrive via physical connections between the stretchable device and an external source, such as a battery. The ability to create a robust physical and electrical connection between mechanically disparate components may enable new types of hybrid devices in which at least a portion is stretchable or deformable, such as hinges. This paper presents a simple method to make mechanical and electrical connections between elastomeric conductors and flexible (or rigid) conductors. The adhesion at the interface between these disparate materials arises from surface chemistry that forms strong covalent bonds. The utilization of liquid metals as the conductor provides stretchable interconnects between stretchable and non-stretchable electrical traces. The liquid metal can be printed or injected into vias to create interconnects. We characterized the mechanical and electrical properties of these hybrid devices to demonstrate the concept and identify geometric design criteria to maximize mechanical strength. The work here provides a simple and general strategy for creating mechanical and electrical connections that may find use in a variety of stretchable and soft electronic devices.}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Erlenbach, Steven and Mondal, Kunal and Ma, Jinwoo and Neumann, Taylor V and Ma, Siyuan and Holbery, James D. and Dickey, Michael D.}, year={2023}, month={Jan} }
 @article{poblete_mondal_ma_dickey_genzer_zhu_2022, title={Direct measurement of rate-dependent mode I and mode II traction-separation laws for cohesive zone modeling of laminated glass}, volume={279}, ISSN={["1879-1085"]}, DOI={10.1016/j.compstruct.2021.114759}, abstractNote={This paper reports a combined experimental-modeling study on the adhesion at glass/poly(vinyl butyral) (PVB) interfaces. PVB is a critical component in laminated glasses that provides impact resistance and prevents spallation in the event of glass breakage. We characterize the mode I (normal) and mode II (shear) interfacial fracture behaviors in glass/PVB/glass laminates and obtained independent cohesive (traction–separation) laws for the two modes. We observe a pronounced rate dependence of both traction-separation laws. Specifically, with increasing loading rate, the interfacial stiffness, the peak stress, and the fracture toughness increase while the critical opening or shear displacement decreases. These measured traction-separation laws are used as inputs in finite element analysis to predict the mechanical behavior of the peel test, which agrees reasonably well with the experimental results. Finite element analysis of a glass laminate subjected to impact loading demonstrates how the measured interfacial properties can be used to predict the mechanical behavior and failure of laminated glass.}, journal={COMPOSITE STRUCTURES}, author={Poblete, Felipe R. and Mondal, Kunal and Ma, Yinong and Dickey, Michael D. and Genzer, Jan and Zhu, Yong}, year={2022}, month={Jan} }
 @article{park_nallainathan_mondal_sen_dickey_2018, title={Light-Induced Buckles Localized by Polymeric Inks Printed on Bilayer Films}, volume={14}, ISSN={["1613-6829"]}, url={https://doi.org/10.1002/smll.201704460}, DOI={10.1002/smll.201704460}, abstractNote={AbstractBuckling instabilities generate microscale features in thin films in a facile manner. Buckles can form, for example, by heating a metal/polymer film stack on a rigid substrate. Thermal expansion differences of the individual layers generate compressive stress that causes the metal to buckle over the entire surface. The ability to dictate and confine the location of buckle formation can enable patterns with more than one length scale, including hierarchical patterns. Here, sacrificial “ink” patterned on top of the film stack localizes the buckles via two mechanisms. First, stiff inks suppress buckles such that only the non‐inked regions buckle in response to infrared light. The metal in the non‐inked regions absorbs the infrared light and thus gets sufficiently hot to induce buckles. Second, soft inks that absorb light get hot faster than the non‐inked regions and promote buckling when exposed to visible light. The exposed metal in the non‐inked regions reflects the light and thus never get sufficiently hot to induce buckles. This second method works on glass substrates, but not silicon substrates, due to the superior thermal insulation of glass. The patterned ink can be removed, leaving behind hierarchical patterns consisting of regions of buckles among non‐buckled regions.}, number={20}, journal={SMALL}, publisher={Wiley}, author={Park, Sungjune and Nallainathan, Umaash and Mondal, Kunal and Sen, Pratik and Dickey, Michael D.}, year={2018}, month={May} }
 @article{barbee_mondal_deng_bharambe_neumann_adams_boechler_dickey_craig_2018, title={Mechanochromic Stretchable Electronics}, volume={10}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.8b09130}, DOI={10.1021/acsami.8b09130}, abstractNote={Soft and stretchable electronics are promising for a variety of applications such as wearable electronics, human-machine interfaces, and soft robotics. These devices, which are often encased in elastomeric materials, maintain or adjust their functionality during deformation, but can fail catastrophically if extended too far. Here, we report new functional composites in which stretchable electronic properties are coupled to molecular mechanochromic function, enabling at-a-glance visual cues that inform user control. These properties are realized by covalently incorporating a spiropyran mechanophore within poly(dimethylsiloxane) to indicate with a visible color change that a strain threshold has been reached. The resulting colorimetric elastomers can be molded and patterned so that, for example, the word "STOP" appears when a critical strain is reached, indicating to the user that further strain risks device failure. We also show that the strain at color onset can be controlled by layering silicones with different moduli into a composite. As a demonstration, we show how color onset can be tailored to indicate a when a specified frequency of a stretchable liquid metal antenna has been reached. The multiscale combination of mechanochromism and soft electronics offers a new avenue to empower user control of strain-dependent properties for future stretchable devices.}, number={35}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Barbee, Meredith H. and Mondal, Kunal and Deng, John Z. and Bharambe, Vivek and Neumann, Taylor V. and Adams, Jacob J. and Boechler, Nicholas and Dickey, Michael D. and Craig, Stephen L.}, year={2018}, month={Sep}, pages={29918–29924} }
 @article{andrews_mondal_neumann_cardenas_wang_parekh_lin_ballentine_dickey_franklin_et al._2018, title={Patterned Liquid Metal Contacts for Printed Carbon Nanotube Transistors}, volume={12}, ISSN={["1936-086X"]}, url={https://doi.org/10.1021/acsnano.8b00909}, DOI={10.1021/acsnano.8b00909}, abstractNote={Flexible and stretchable electronics are poised to enable many applications that cannot be realized with traditional, rigid devices. One of the most promising options for low-cost stretchable transistors are printed carbon nanotubes (CNTs). However, a major limiting factor in stretchable CNT devices is the lack of a stable and versatile contact material that forms both the interconnects and contact electrodes. In this work, we introduce the use of eutectic gallium-indium (EGaIn) liquid metal for electrical contacts to printed CNT channels. We analyze thin-film transistors (TFTs) fabricated using two different liquid metal deposition techniques-vacuum-filling polydimethylsiloxane (PDMS) microchannel structures and direct-writing liquid metals on the CNTs. The highest performing CNT-TFT was realized using vacuum-filled microchannel deposition with an in situ annealing temperature of 150 °C. This device exhibited an on/off ratio of more than 104 and on-currents as high as 150 μA/mm-metrics that are on par with other printed CNT-TFTs. Additionally, we observed that at room temperature the contact resistances of the vacuum-filled microchannel structures were 50% lower than those of the direct-write structures, likely due to the poor adhesion between the materials observed during the direct-writing process. The insights gained in this study show that stretchable electronics can be realized using low-cost and solely solution processing techniques. Furthermore, we demonstrate methods that can be used to electrically characterize semiconducting materials as transistors without requiring elevated temperatures or cleanroom processes.}, number={6}, journal={ACS NANO}, publisher={American Chemical Society (ACS)}, author={Andrews, Joseph B. and Mondal, Kunal and Neumann, Taylor V. and Cardenas, Jorge A. and Wang, Justin and Parekh, Dishit P. and Lin, Yiliang and Ballentine, Peter and Dickey, Michael and Franklin, Aaron D. and et al.}, year={2018}, month={Jun}, pages={5482–5488} }
 @inproceedings{mondal_gupta_2018, title={Recent advances in carbon-semiconductor nanocomposites for water remediation}, booktitle={Water remediation}, author={Mondal, K. and Gupta, A.}, year={2018}, pages={45–74} }
 @inproceedings{gupta_mondal_kumar_2018, title={Role of photo-catalysis in water remediation}, booktitle={Water remediation}, author={Gupta, A. and Mondal, K. and Kumar, S.}, year={2018}, pages={117–134} }
 @article{park_mondal_treadway_kumar_ma_holbery_dickey_2018, title={Silicones for Stretchable and Durable Soft Devices: Beyond Sylgard-184}, volume={10}, ISSN={["1944-8252"]}, url={https://doi.org/10.1021/acsami.7b18394}, DOI={10.1021/acsami.7b18394}, abstractNote={This paper identifies and characterizes silicone elastomers that are well-suited for fabricating highly stretchable and tear-resistant devices that require interfacial bonding by plasma or UV ozone treatment. The ability to bond two or more pieces of molded silicone is important for creating microfluidic channels, chambers for pneumatically driven soft robotics, and other soft and stretchable devices. Sylgard-184 is a popular silicone, particularly for microfluidic applications. However, its low elongation at break (∼100% strain) and moderate tear strength (∼3 N/mm) make it unsuitable for emerging, mechanically demanding applications of silicone. In contrast, commercial silicones, such as Dragon Skin, have excellent mechanical properties yet are difficult to plasma-bond, likely because of the presence of silicone oils that soften the network yet migrate to the surface and interfere with plasma bonding. We found that extracting silicone oligomers from these soft networks allows these materials to bond but only when the Shore hardness exceeds a value of 15 A. It is also possible to mix highly stretchable silicones (Dragon Skin and Ecoflex) with Sylgard-184 to create silicones with intermediate mechanical properties; interestingly, these blends also only bond when the hardness exceeds 15 A. Eight different Pt-cured silicones were also screened; again, only those with Shore hardness above 15 A plasma-bond. The most promising silicones from this study are Sylgard-186 and Elastosil-M4130 and M4630, which exhibit a large deformation (>200% elongation at break), high tear strength (>12 N/mm), and strong plasma bonding. To illustrate the utility of these silicones, we created stretchable electrodes by injecting a liquid metal into microchannels created using such silicones, which may find use in soft robotics, electronic skin, and stretchable energy storage devices.}, number={13}, journal={ACS APPLIED MATERIALS & INTERFACES}, publisher={American Chemical Society (ACS)}, author={Park, Sungjune and Mondal, Kunal and Treadway, Robert M., III and Kumar, Vikash and Ma, Siyuan and Holbery, James D. and Dickey, Michael D.}, year={2018}, month={Apr}, pages={11261–11268} }
 @article{mondal_ali_singh_sumana_malhotra_sharma_2017, title={Highly sensitive porous carbon and metal/carbon conducting nanofiber based enzymatic biosensors for triglyceride detection}, volume={246}, ISSN={["0925-4005"]}, DOI={10.1016/j.snb.2017.02.050}, abstractNote={Electrospinning was employed to synthesize a Ag nanoparticle (NP)-impregnated partially aligned and free-standing carbon nanofibers (CNFs) mat using a polyacrylonitrile (PAN) and silver nitrate blend followed by carbonization. Pyrolyzation of the PAN/AgNO3 blend produced the nanoporous CNFs, and the Ag NPs were grown within the CNFs via thermal decomposition of AgNO3. The fiber diameters of the synthesized CNFs ranged from 130 to 190 nm, and the size of the impregnated Ag NPs was ∼30 nm. The presence of the Ag NPs enhanced the electrical conductivity and promoted graphitization of the CNFs via the templating effect of the Ag NPs. These synthesized CNFs and AgCNFs nanocomposite were electrophoretically deposited onto indium tin oxide electrodes for detection of triglyceride molecules. Oxygen plasma treatment of the CNFs and AgCNFs surfaces resulted in enhanced loading of lipase and glycerol dehydrogenase bienzymes. The AgCNFs nanocomposite exhibited faster electron transfer than the CNFs, as corroborated by electrochemical impedance spectroscopy and cyclic voltammetry studies. Covalent functionalization via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide coupling chemistry on a nanoporous CNFs surface led to higher stability of the fabricated biosensor toward triglyceride detection. The sensitivity was four-fold higher for the AgCNFs (1.232 μA mg/dL−1 cm−2) bioelectrode compared with the CNFs (0.33 μA mg/dL−1 cm−2) over a wide detection range (25–500 mg/dL). These biosensors exhibited excellent selectivity, good reproducibility, and faster response (10 s). Thus, enhanced graphitization and electrical conductivity of nanoporous CNFs via incorporation of Ag NPs yields a promising platform for the detection of triglyceride (TG) biomolecules.}, journal={SENSORS AND ACTUATORS B-CHEMICAL}, author={Mondal, Kunal and Ali, Md. Azahar and Singh, Chandan and Sumana, Gajjala and Malhotra, Bansi D. and Sharma, Ashutosh}, year={2017}, month={Jul}, pages={202–214} }
 @inproceedings{ali_mondal_wang_mahal_castellano_dong_2017, title={Microfluidic detection of soil nitrate ions using novel electrochemical foam electrode}, booktitle={30th ieee international conference on micro electro mechanical systems (mems 2017)}, author={Ali, M. A. and Mondal, K. and Wang, Y. F. and Mahal, N. K. and Castellano, M. J. and Dong, L.}, year={2017}, pages={482–485} }
 @article{singh_mondal_sharma_2017, title={ZnO Nanoparticle Fortified Highly Permeable Carbon/Silica Monoliths as a Flow-Through Media}, volume={33}, ISSN={["0743-7463"]}, DOI={10.1021/acs.langmuir.7b01361}, abstractNote={We demonstrate a facile one-pot synthesis of porous "flow-through" ZnO nanoparticle impregnated carbon/silica monoliths with high mechanical strength and interconnected end-to-end pores decorated with functional and catalytic nanoparticles. The materials and conditions for the synthesis were tailored to achieve the desired properties of high mechanical strength, good flow-through permeability, and crack-free morphology. Monoliths were prepared from a resorcinol formaldehyde rout but with the addition of tetraethyl-orthosilicate and a metal oxide precursor, ZnCl2. The monoliths were ambient dried and carbonized under optimized conditions to suppress cracks. Compressive tests of both the resin and carbonized monoliths were performed to examine the effect of the metal oxide precursor on the mechanical properties. The permeability of the monoliths was determined to verify their utility as a flow-through material. The monoliths exhibited a high compressive modulus of ∼30 MPa compared with conventional carbon aerogels and a permeability of ∼10-12 m2. Various characterization techniques were used to analyze the surface morphology, pore texture, and chemical composition of the monoliths. Finally, Ag nanoparticles were incorporated in the monoliths to demonstrate an example of a "flow-through" catalysis application where controlled catalytic conversion of para-nitrophenol into para-aminophenol could be achieved in a continuous flow reactor mode.}, number={31}, journal={LANGMUIR}, author={Singh, Srujan and Mondal, Kunal and Sharma, Ashutosh}, year={2017}, month={Aug}, pages={7692–7700} }
 @article{srivastava_mondal_mukhopadhyay_prasad_sharma_2016, title={Facile reduction of para-nitrophenols: catalytic efficiency of silver nanoferns in batch and continuous flow reactors}, volume={6}, ISSN={["2046-2069"]}, DOI={10.1039/c6ra21977b}, abstractNote={Catalytic application of Ag-nanoferns grown over carbon microfibers by electrodeposition and compatible reactor design for batch and continuous flow operations.}, number={115}, journal={RSC ADVANCES}, author={Srivastava, Alok Kumar and Mondal, Kunal and Mukhopadhyay, Kingsuk and Prasad, N. Eswara and Sharma, Ashutosh}, year={2016}, pages={113981–113990} }
 @article{ali_mondal_wang_jiang_mahal_castellano_sharma_dong_2017, title={In situ integration of graphene foam-titanium nitride based bio-scaffolds and microfluidic structures for soil nutrient sensors}, volume={17}, DOI={10.1039/c6lc01266c}, abstractNote={Bio-scaffolds of graphene foam–titanium nitride composites are embedded into a microfluidic channel to detect nitrate ions in agricultural soils.}, number={2}, journal={Lab on a Chip}, author={Ali, M. A. and Mondal, K. and Wang, Y. F. and Jiang, H. W. and Mahal, N. K. and Castellano, M. J. and Sharma, A. and Dong, L.}, year={2017}, pages={274–285} }
 @article{mondal_kumar_sharma_2016, title={Metal-Oxide Decorated Multilayered Three-Dimensional (3D) Porous Carbon Thin Films for Supercapacitor Electrodes}, volume={55}, ISSN={["0888-5885"]}, DOI={10.1021/acs.iecr.6b03396}, abstractNote={We demonstrate an easy, scalable, and two-step synthesis of macroporous carbon, carbon/TiO2 (cTiO2), carbon/MnO2 (cMnO2), and carbon/TiO2/MnO2 (cTiO2/MnO2) composite thin films for energy storage applications. The direct synthesis of the hybrid films was achieved by spin coating, followed by carbonization. The unique multilayered three-dimensional (3D) pore structure of the film permits the synthesis of carbon/TiO2/MnO2 nanocomposites with enhanced metal-oxide nanoparticle loading up to 50 wt %. The as-synthesized porous carbon thin films were tested for their supercapacitor activity and a maximum specific capacitance ∼44 F g–1 was achieved with a film thickness of 350 nm. The as-prepared cTiO2, cMnO2, and cTiO2/MnO2 electrodes exhibit high specific capacitances of 178, 237, and 297 F g–1, respectively, at 5 mV s–1, because of their unique properties with impregnated nanoparticles, and direct fabrication on conductive substrates. This simple scalable coating technique is compatible with the high-speed rol...}, number={49}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Mondal, Kunal and Kumar, Rudra and Sharma, Ashutosh}, year={2016}, month={Dec}, pages={12569–12581} }
 @article{ali_mondal_jiao_oren_xu_sharma_dong_2016, title={Microfluidic Immuno-Biochip for Detection of Breast Cancer Biomarkers Using Hierarchical Composite of Porous Graphene and Titanium Dioxide Nanofibers}, volume={8}, ISSN={["1944-8252"]}, DOI={10.1021/acsami.6b05648}, abstractNote={We report on a label-free microfluidic immunosensor with femtomolar sensitivity and high selectivity for early detection of epidermal growth factor receptor 2 (EGFR2 or ErbB2) proteins. This sensor utilizes a uniquely structured immunoelectrode made of porous hierarchical graphene foam (GF) modified with electrospun carbon-doped titanium dioxide nanofibers (nTiO2) as an electrochemical working electrode. Due to excellent biocompatibility, intrinsic surface defects, high reaction kinetics, and good stability for proteins, anatase nTiO2 are ideal for electrochemical sensor applications. The three-dimensional and porous features of GF allow nTiO2 to penetrate and attach to the surface of the GF by physical adsorption. Combining GF with functional nTiO2 yields high charge transfer resistance, large surface area, and porous access to the sensing surface by the analyte, resulting in new possibilities for the development of electrochemical immunosensors. Here, the enabling of EDC-NHS chemistry covalently immobilized the antibody of ErbB2 (anti-ErbB2) on the GF-nTiO2 composite. To obtain a compact sensor architecture, the composite working electrode was designed to hang above the gold counter electrode in a microfluidic channel. The sensor underwent differential pulse voltammetry and electrochemical impedance spectroscopy to quantify breast cancer biomarkers. The two methods had high sensitivities of 0.585 μA μM(-1) cm(-2) and 43.7 kΩ μM(-1) cm(-2) in a wide concentration range of target ErbB2 antigen from 1 × 10(-15) M (1.0 fM) to 0.1 × 10(-6) M (0.1 μM) and from 1 × 10(-13) M (0.1 pM) to 0.1 × 10(-6) M (0.1 μM), respectively. Utilization of the specific recognition element, i.e., anti-ErbB2, results in high specificity, even in the presence of identical members of the EGFR family of receptor tyrosine kinases, such as ErbB3 and ErbB4. Many promising applications in the field of electrochemical detection of chemical and biological species will derive from the integration of the porous GF-nTiO2 composite into microfluidic devices.}, number={32}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Ali, Md. Azahar and Mondal, Kunal and Jiao, Yueyi and Oren, Seval and Xu, Zhen and Sharma, Ashutosh and Dong, Liang}, year={2016}, month={Aug}, pages={20570–20582} }
 @misc{mondal_sharma_2016, title={Recent advances in electrospun metal-oxide nanofiber based interfaces for electrochemical biosensing}, volume={6}, ISSN={["2046-2069"]}, DOI={10.1039/c6ra21477k}, abstractNote={Synthesis of various electrospun metal-oxide nanofibers and their application towards electrochemical enzymatic and enzyme-free biosensor platforms has been critically discussed.}, number={97}, journal={RSC ADVANCES}, author={Mondal, Kunal and Sharma, Ashutosh}, year={2016}, pages={94595–94616} }
 @misc{mondal_sharma_2016, title={Recent advances in the synthesis and application of photocatalytic metal-metal oxide core-shell nanoparticles for environmental remediation and their recycling process}, volume={6}, ISSN={["2046-2069"]}, DOI={10.1039/c6ra18102c}, abstractNote={Metal–metal oxide core–shell nanoparticles have received enormous research attention owing to their fascinating physicochemical properties and extensive applications. In this review we have discussed the challenges and recent advances in their synthesis and application.}, number={87}, journal={RSC ADVANCES}, author={Mondal, Kunal and Sharma, Ashutosh}, year={2016}, pages={83589–83612} }