@article{wei_ghosh_2024, title={Moisture-Driven Cellulose Actuators with Directional Motion and Programmable Shapes}, volume={2}, ISSN={["2640-4567"]}, url={https://doi.org/10.1002/aisy.202300638}, DOI={10.1002/aisy.202300638}, abstractNote={The hygroscopic motion of plants has inspired the development of moisture‐activated soft actuators. These actuators driven by ambient moisture sources are of great research interest in robotics and self‐regulating textiles. However, these actuators often have slow motion and can only perform bending and twisting motions. Herein, a cellulose film‐based fast‐morphing and motion‐programmable soft actuator is presented that can generate caterpillar‐like movement. The cellophane films reported here bend almost instantaneously under changing humidity, with a large bending curvature, high repeatability, and negligible hysteresis. Different actuation modes are studied using both coated and uncoated cellophane films. The uncoated cellophane film can continuously move on a moist substrate through autonomous bending–rolling–flipping (or oscillating) cycles. A facile strategy is used here to control the rolling direction and facilitate the flipping motion by offsetting its center of gravity during deformation by adding appropriate weights on the end of the actuator. The coated cellophane film is used to fabricate motion‐programmable actuators through heat‐laminating. Several actuator structures are designed and fabricated and their diverse moisture‐induced motions are demonstrated.}, journal={ADVANCED INTELLIGENT SYSTEMS}, author={Wei, Shuzhen and Ghosh, Tushar K.}, year={2024}, month={Feb} }
 @article{wei_ghosh_2022, title={Bioinspired Structures for Soft Actuators}, volume={4}, ISSN={["2365-709X"]}, url={https://doi.org/10.1002/admt.202101521}, DOI={10.1002/admt.202101521}, abstractNote={Abstract}, journal={ADVANCED MATERIALS TECHNOLOGIES}, publisher={Wiley}, author={Wei, Shuzhen and Ghosh, Tushar K.}, year={2022}, month={Apr} }
 @article{cheng_yan_orenstein_dirican_wei_subjalearndee_zhang_2022, title={Polyacrylonitrile Nanofiber-Reinforced Flexible Single-Ion Conducting Polymer Electrolyte for High-Performance, Room-Temperature All-Solid-State Li-Metal Batteries}, volume={4}, ISSN={["2524-793X"]}, url={https://doi.org/10.1007/s42765-021-00128-1}, DOI={10.1007/s42765-021-00128-1}, number={3}, journal={ADVANCED FIBER MATERIALS}, publisher={Springer Science and Business Media LLC}, author={Cheng, Hui and Yan, Chaoyi and Orenstein, Raphael and Dirican, Mahmut and Wei, Shuzhen and Subjalearndee, Nakarin and Zhang, Xiangwu}, year={2022}, month={Jan} }
 @article{wei_ghosh_2021, title={Bioinspired Bistable Dielectric Elastomer Actuators: Programmable Shapes and Application as Binary Valves}, volume={11}, ISSN={["2169-5180"]}, url={https://doi.org/10.1089/soro.2020.0214}, DOI={10.1089/soro.2020.0214}, abstractNote={Nature has plenty of imitable examples of bistable thin structures that can actuate in response to mechanical and environmental stimuli, such as touch, light, and moisture. Scientists and engineers have used these as models to develop real-world systems with enhanced shape stability, energy efficiency, and power output. The bistable leaf of the Venus Flytrap (VFT) has a uniquely simple structure that enables exquisite actuation to trap the prey instantly. In this study, we present a strategy, inspired and derived from the VFT, which incorporates dielectric elastomer (DE) layers in a bistable actuator capable of reversible snapping through electrical stimulation. The trilayered laminated actuator is composed of two prestrained layers and a strain-limiting middle layer. The balance between elastic energy and bending energy of the laminates results in bistable shapes. We explore a broad design space of the bistable architecture through analysis and experiments to validate the fabrication parameters. The rapid snap-through between the two stable configurations is activated by a voltage pulse applied on the DE layers that change the laminate's strain field. Whereas a high electric field is used as the actuation trigger, the self-stabilization characteristic of the bistable structure obviates the need for continuous voltage supply. Finally, we recommended a new method of flow control by modulating porosity on curved surfaces through operating bistable dielectric elastomer actuators as binary valves.}, journal={SOFT ROBOTICS}, author={Wei, Shuzhen and Ghosh, Tushar K.}, year={2021}, month={Nov} }
 @article{wei_shao_ghosh_2019, title={Bioinspired Bistable Soft Actuators}, volume={10966}, ISSN={["1996-756X"]}, DOI={10.1117/12.2522123}, abstractNote={DEAs have been studied for decades as a potential polymer artificial muscle for its excellent mechanical properties and large electric field-induced strains. The structural design of DEAs enhances the actuator performances and converts the electrically–controlled strain to diverse motions including linear motion, bending, twisting and moving with multiple degree of freedom. Inspired by the Venus Flytrap (VFT), whose bistable leaves and local strain redistribution are crucial to the fast closure speed, we developed cylindrically-curved bistable laminated DEAs, and activated the bistable shape transformation by electrically tuning the strain field. To obtain the bistable structure, two elastomeric films are prestrained biaxially and bonded orthogonally to a stiffer elastic film in the middle. Due to the elastic energy minimization, the originally flat laminate immediately self-equilibrated to two bistable cylindrical shapes, with the curvatures orthogonal to each other. Basic theoretical analyses on the interaction of prestrains and bending curvatures provide guidance to the design of bistable morphing shapes. The prestrains on the DE films not only generate various curved shapes, but also decreases the film thickness and therefore reduces the actuation voltage. Similar to the fast closure of VFT, which is activated by the strain redistribution resulted from the motor cell enlargement, our bistable DEA achieves reversible bistable shape transformation by voltage-induced strain change at the area covered by compliant electrodes.}, journal={ELECTROACTIVE POLYMER ACTUATORS AND DEVICES (EAPAD) XXI}, author={Wei, S. and Shao, H. and Ghosh, T. K.}, year={2019} }