@article{yang_kwon_kanetkar_xing_nithyanandam_li_jung_gong_tuman_shen_et al._2021, title={Skin-Inspired Capacitive Stress Sensor with Large Dynamic Range via Bilayer Liquid Metal Elastomers}, volume={11}, ISSN={["2365-709X"]}, DOI={10.1002/admt.202101074}, abstractNote={AbstractSoft devices that sense touch are important for prosthetics, soft robotics, and electronic skins. One way to sense touch is to use a capacitor consisting of a soft dielectric layer sandwiched between two electrodes. Compressing the capacitor brings the electrodes closer together and thereby increases capacitance. Ideally, sensors of touch should have both large sensitivity and the ability to measure a wide range of stress (dynamic range). Although skin has such capabilities, it remains difficult to achieve both sensitivity and dynamic range in a single manmade sensor. Inspired by skin, this work reports a soft capacitive pressure sensor based on a bilayer of liquid metal elastomer foam (B‐LMEF). The B‐LMEF consists of an elastomer slab (elastic modulus: ≈655 kPa) laminated with a soft liquid metal elastomer foam (LMEF, elastic modulus: ≈7 kPa). The LMEF deforms at small stresses (<10 kPa), and both layers deform at large stresses (>10 kPa). The B‐LMEF has high sensitivity (0.073 kPa–1) at small stress and can operate over a large range of stress (200 kPa), which leads to a large dynamic range (≈4.1 × 105). Additionally, the elastomer slab has a large energy dissipation coefficient; the skin uses this property to cushion the human body from external stress and strain.}, journal={ADVANCED MATERIALS TECHNOLOGIES}, author={Yang, Jiayi and Kwon, Ki Yoon and Kanetkar, Shreyas and Xing, Ruizhe and Nithyanandam, Praneshnandan and Li, Yang and Jung, Woojin and Gong, Wei and Tuman, Mary and Shen, Qingchen and et al.}, year={2021}, month={Nov} }
 @misc{chatterjee_ghosh_2021, title={Thermoelectric Materials for Textile Applications}, volume={26}, ISSN={["1420-3049"]}, url={https://doi.org/10.3390/molecules26113154}, DOI={10.3390/molecules26113154}, abstractNote={Since prehistoric times, textiles have served an important role–providing necessary protection and comfort. Recently, the rise of electronic textiles (e-textiles) as part of the larger efforts to develop smart textiles, has paved the way for enhancing textile functionalities including sensing, energy harvesting, and active heating and cooling. Recent attention has focused on the integration of thermoelectric (TE) functionalities into textiles—making fabrics capable of either converting body heating into electricity (Seebeck effect) or conversely using electricity to provide next-to-skin heating/cooling (Peltier effect). Various TE materials have been explored, classified broadly into (i) inorganic, (ii) organic, and (iii) hybrid organic-inorganic. TE figure-of-merit (ZT) is commonly used to correlate Seebeck coefficient, electrical and thermal conductivity. For textiles, it is important to think of appropriate materials not just in terms of ZT, but also whether they are flexible, conformable, and easily processable. Commercial TEs usually compromise rigid, sometimes toxic, inorganic materials such as bismuth and lead. For textiles, organic and hybrid TE materials are more appropriate. Carbon-based TE materials have been especially attractive since graphene and carbon nanotubes have excellent transport properties with easy modifications to create TE materials with high ZT and textile compatibility. This review focuses on flexible TE materials and their integration into textiles.}, number={11}, journal={MOLECULES}, publisher={MDPI AG}, author={Chatterjee, Kony and Ghosh, Tushar K.}, year={2021}, month={Jun} }
 @inbook{fang_chatterjee_kapoor_ghosh_2020, place={Weinheim, Germany}, title={Fiber-Based Sensors and Actuators}, ISBN={9783527342204}, url={http://dx.doi.org/10.1002/9783527342587.ch25}, DOI={10.1002/9783527342587.ch25}, abstractNote={Wearable electronics have evolved from personal pocket-size devices to smart glasses and watches, athletic apparel with biomonitoring capabilities, and high fashion garments with responsive designs. Integration of electronic devices that are traditionally rigid into textile form factors that can be worn for on-body applications also dubbed as electronic textiles (e-textiles) are well underway. Textiles used as clothing provide an excellent medium for the deployment of flexible electronics due their intimate contact with the human body. While the new area of innovative research and commercialization of e-textile products offer many opportunities the challenges are to preserve the quintessential qualities of textiles such as flexibility, porosity, bulk, and texture essential for clothing and others. In this chapter, we review the integration of sensors and actuators into fibrous form factors for various wearable electronic applications. Since sensors and actuators are closely linked in terms of providing a measurable response to an external stimulus, we envisage a closed loop personal comfort system where both are integrated to create an autonomous system of control without the need for external intervention. Hence, research in this field is particularly of interest both from a materials perspective as well as from a structure and performance perspective.}, booktitle={Handbook of Fibrous Materials}, publisher={Wiley-VCH}, author={Fang, X. and Chatterjee, K. and Kapoor, A. and Ghosh, T.K.}, editor={Hu, Jinlian and Kumar, Bipin and Lu, JingEditors}, year={2020}, pages={681–720} }
 @article{armstrong_chatterjee_ghosh_spontak_2020, title={Form-stable phase-change elastomer gels derived from thermoplastic elastomer copolyesters swollen with fatty acids}, volume={686}, ISSN={["1872-762X"]}, url={http://dx.doi.org/10.1016/j.tca.2020.178566}, DOI={10.1016/j.tca.2020.178566}, abstractNote={Phase-change materials (PCMs) are of considerable scientific and technological interest in applications related to energy management and storage, especially as they pertain to residential or commercial construction and packaging. Most PCMs developed for these purposes consist of a crystallizable species encapsulated within an impermeable polymeric shell. Such encapsulants can then be strategically embedded throughout a construct to promote thermal stability in close proximity to the normal melting point of the encapsulated species. In this study, we introduce form-stable PCMs, which avoid the need for costly and inconvenient encapsulation and consist of commercial thermoplastic elastomer copolyesters selectively swollen with crystallizable fatty acids. Since the copolyester matrices endow the PCMs with solid-like characteristics even when swollen with liquid, we refer to this particular class of materials as phase-change elastomer gels (PCEGs). In this study, we explore the thermal characteristics of PCEG films wherein the copolyester grade, gel composition and fatty acid are all varied. Our results indicate that these PCEGs exhibit non-hysteretic thermal cycling, unaffected transition temperatures, and competitive latent transition heats. Relative to model and commercially available encapsulated PCMs, the form-stable PCEGs examined here afford an alternative capable of superior thermal performance and versatility.}, journal={THERMOCHIMICA ACTA}, author={Armstrong, Daniel P. and Chatterjee, Kony and Ghosh, Tushar K. and Spontak, Richard J.}, year={2020}, month={Apr} }
 @article{chatterjee_negi_kim_liu_ghosh_2020, title={In-Plane Thermoelectric Properties of Flexible and Room-Temperature-Doped Carbon Nanotube Films}, volume={3}, url={https://doi.org/10.1021/acsaem.0c00995}, DOI={10.1021/acsaem.0c00995}, abstractNote={Soft materials with high power factors (PFs) and low thermal conductivity (κ) are critically important for integration of thermoelectric (TE) modules into flexible form factors for energy harvestin...}, number={7}, journal={ACS Applied Energy Materials}, publisher={American Chemical Society (ACS)}, author={Chatterjee, Kony and Negi, Ankit and Kim, Kyunghoon and Liu, Jun and Ghosh, Tushar K.}, year={2020}, month={Jul}, pages={6929–6936} }
 @article{tabor_chatterjee_ghosh_2020, title={Smart Textile‐Based Personal Thermal Comfort Systems: Current Status and Potential Solutions}, url={http://dx.doi.org/10.1002/admt.201901155}, DOI={10.1002/admt.201901155}, abstractNote={AbstractThermophysiological comfort in humans is sought universally but seldom achieved due to biological and physiological variances. Most people in developed parts of the world rely on highly energy‐intensive, and inefficient central heating/cooling systems to achieve thermophysiological comfort which is rarely satisfactory. A potential solution to this issue is a wearable personal thermal comfort system (PTCS) consisting of textile‐based temperature and moisture sensors, thermal and moisture responsive actuators, and/or heating/cooling devices, that can sense the environment and physiology of the wearer, and accordingly provide an individualized thermal environment. Moving thermal regulation away from the built environment to the microclimate surrounding the human body using textiles has the potential to provide personalized thermal comfort and energy savings. Such a system may employ thermal comfort models and leverage the Internet of Things (IoT) and machine learning (ML) to understand individuals' comfort requirements. Herein, the current state of textile‐based active and passive comfort systems/technologies are summarized, including their environmental impact, major thermal comfort models, and factors influencing comfort. Also, active and passive textile‐based devices (sensors, actuators, and flexible heating/cooling devices) that may be incorporated into a textile‐based wearable PTCS are comprehensively discussed with an emphasis on their advantages, limitations, and prospects.}, journal={Advanced Materials Technologies}, author={Tabor, Jordan and Chatterjee, Kony and Ghosh, Tushar K.}, year={2020}, month={Mar} }
 @article{chatterjee_ghosh_2020, title={3D Printing of Textiles: Potential Roadmap to Printing with Fibers}, volume={32}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85075933322&partnerID=MN8TOARS}, DOI={10.1002/adma.201902086}, abstractNote={Abstract3D printing (3DP) has transformed engineering, manufacturing, and the use of advanced materials due to its ability to produce objects from a variety of materials, ranging from soft polymers to rigid ceramics. 3DP offers the advantage of being able to print at a variety of lengths scales; from a few micrometers to many meters. 3DP has the unique ability to produce customized small lots, efficiently. Yet, one crucial industry that has not been able to adequately explore its potential is textile manufacturing. The research in 3DP of textiles has lagged behind other areas primarily due to the difficulty in obtaining some of the unique characteristics of strength, flexibility, etc., of textiles, utilizing a fundamentally different manufacturing technology. Textiles are their own class of materials due to the specific structural developments that occur during the various stages of textile manufacturing: from fiber extrusion to assembly of the fibers to fabrics. Here, the current 3DP technologies are reviewed with emphasis on soft and anisotropic structures, as well as the efforts toward 3DP of textiles. Finally, a potential pathway to 3DP of textiles, dubbed as printing with fibers to create textile structures is proposed for further exploration.}, number={4}, journal={Advanced Materials}, publisher={Wiley}, author={Chatterjee, Kony and Ghosh, Tushar}, year={2020}, month={Jan}, pages={1902086} }
 @misc{chatterjee_tabor_ghosh_2019, title={Electrically Conductive Coatings for Fiber-Based E-Textiles}, volume={7}, ISSN={["2079-6439"]}, url={https://doi.org/10.3390/fib7060051}, DOI={10.3390/fib7060051}, abstractNote={With the advent of wearable electronic devices in our daily lives, there is a need for soft, flexible, and conformable devices that can provide electronic capabilities without sacrificing comfort. Electronic textiles (e-textiles) combine electronic capabilities of devices such as sensors, actuators, energy harvesting and storage devices, and communication devices with the comfort and conformability of conventional textiles. An important method to fabricate such devices is by coating conventionally used fibers and yarns with electrically conductive materials to create flexible capacitors, resistors, transistors, batteries, and circuits. Textiles constitute an obvious choice for deployment of such flexible electronic components due to their inherent conformability, strength, and stability. Coating a layer of electrically conducting material onto the textile can impart electronic capabilities to the base material in a facile manner. Such a coating can be done at any of the hierarchical levels of the textile structure, i.e., at the fiber, yarn, or fabric level. This review focuses on various electrically conducting materials and methods used for coating e-textile devices, as well as the different configurations that can be obtained from such coatings, creating a smart textile-based system.}, number={6}, journal={FIBERS}, publisher={MDPI AG}, author={Chatterjee, Kony and Tabor, Jordan and Ghosh, Tushar K.}, year={2019}, month={Jun} }
 @misc{agcayazi_chatterjee_bozkurt_ghosh_2018, title={Flexible Interconnects for Electronic Textiles}, volume={3}, ISSN={["2365-709X"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85041134838&partnerID=MN8TOARS}, DOI={10.1002/admt.201700277}, abstractNote={AbstractConformable electrical systems integrated in textiles offer revolutionary possibilities. Textiles constitute an obvious choice as a multifunctional electronic platform, since they are worn and used to cover many surfaces around us. The primary focus of the emerging area of electronic textiles (e‐textiles) is on developing transformative technologies to produce flexible, conformable, and large‐area textile‐based electronic systems. One of the main roadblocks to development of e‐textiles is making (fiber‐to‐fiber) interconnects within textiles, with rigid semiconductor‐based circuits and other devices, and efficiently routing these circuits. This problem is compounded by the need for the textile and other materials to withstand the stresses and strains of manufacturing and end‐use. The fundamental challenge of forming these interconnects involves making them flexible, robust, and environmentally stable while ensuring adequate electrical connectivity. From a mechanical standpoint, the transition from soft to hard materials should occur with minimum stress/strain concentration. These challenges, if unaddressed, will remain a barrier to large‐scale development of textile‐based electronic systems. This work reviews the technological issues related to the textile interconnect, providing an overview of flexible interconnects, including relevant materials, electrical and mechanical characterization techniques, ways of forming flexible conductive pathways, and potential research directions and challenges.}, number={10}, journal={ADVANCED MATERIALS TECHNOLOGIES}, author={Agcayazi, Talha and Chatterjee, Kony and Bozkurt, Alper and Ghosh, Tushar K.}, year={2018}, month={Oct} }
 @article{kapoor_mcknight_chatterjee_agcayazi_kausche_bozkurt_ghosh_2018, title={Toward Fully Manufacturable, Fiber Assembly-Based Concurrent Multimodal and Multifunctional Sensors for e-Textiles}, volume={4}, ISSN={2365-709X}, url={http://dx.doi.org/10.1002/ADMT.201800281}, DOI={10.1002/admt.201800281}, abstractNote={AbstractSoft polymer‐based sensors as an integral part of textile structures have attracted considerable scientific and commercial interest recently because of their potential use in healthcare, security systems, and other areas. While electronic sensing functionalities can be incorporated into textiles at one or more of the hierarchical levels of molecules, fibers, yarns, or fabrics, arguably a more practical and inconspicuous means to introduce the desired electrical characteristics is at the fiber level, using processes that are compatible to textiles. Here, a prototype multimodal and multifunctional sensor array formed within a woven fabric structure using bicomponent fibers with ordered insulating and conducting segments is reported. The multifunctional characteristics of the sensors are successfully demonstrated by measuring tactile, tensile, and shear deformations, as well as wetness and biopotential. While the unobtrusive integration of sensing capabilities offers possibilities to preserve all desirable textile qualities, this scaled‐up fiber‐based approach demonstrates the potential for scalable and facile manufacturability of practical e‐textile products using low‐cost roll‐to‐roll processing of large‐area flexible sensor systems and can be remarkably effective in advancing the field of e‐textiles.}, number={1}, journal={Advanced Materials Technologies}, publisher={Wiley}, author={Kapoor, Ashish and McKnight, Michael and Chatterjee, Kony and Agcayazi, Talha and Kausche, Hannah and Bozkurt, Alper and Ghosh, Tushar K.}, year={2018}, month={Oct}, pages={1800281} }
 @inproceedings{kapoor_mcknight_chatterjee_agcayazi_kausche_ghosh_bozkurt_2017, place={Orlando, FL, USA}, title={Soft, flexible 3D printed fibers for capacitive tactile sensing}, url={http://ieeexplore.ieee.org/document/7808918/}, DOI={10.1109/ICSENS.2016.7808918}, abstractNote={This study presents our latest efforts towards developing a force sensor array by weaving 3D printed functionalized polymer fibers. Silicone was used as the base polymer and carbon fillers were used to impart electrical conductivity. Two “H”-shaped fiber cross-sections oriented orthogonally acted as a parallel plate capacitor and were used for detecting normal forces. In this article, we present the fabrication method of the unique “H”-shaped fiber cross-section along with the investigation of the relation between applied force and measured capacitance. We also report the sensor response to variation in temperature. The sensing crossover was found to have a stable mechanical and electrical response in the force range of 0–6 N and the performance of this soft sensor was not significantly affected by temperature.}, booktitle={IEEE Sensors}, author={Kapoor, A. and McKnight, M. and Chatterjee, Kony and Agcayazi, T. and Kausche, H. and ghosh and Bozkurt, A.}, year={2017}, month={Jan}, pages={1–3} }