Intelligent active deformable fabrics are emerging functional materials with promising applications in wearable fabrics, such as the ability to spontaneously adjust their shape to increase wearing comfort or as assistive devices to help humans lift heavy objects more easily. The movement of intelligent deformable fabrics can be triggered in various ways. Among them, deformable fabrics triggered by electrochemical ions have the characteristics of good controllability, large degree of deformation, low voltage, fast response, and unclear thermal effects, which have the potential for application in wearable devices. However, the development of electrochemically driven deformable fabrics is constrained by the liquid working environment.

Recently, Di Jiangtao, a researcher at the Suzhou Institute of Nanotechnology and Nano bionics of the Chinese Academy of Sciences, reported on the active texturing fabric woven with biomimetic muscle fibers driven by electrochemistry. This fabric has the characteristics of low driving voltage and fast response speed, and can work stably in the air without liquid environment. Research has found that controlling fiber shrinkage in different areas of the fabric can achieve active deformation of the fabric as a whole and locally. The study preliminarily demonstrated the potential application of the electrochemical driven active deformation fabric in wearable power assisted fabrics.

This study used carbon nanotube (CNT) composite fibers as raw materials for biomimetic muscle fibers, and developed a continuous preparation technology for biomimetic muscle fibers. By controlling the relative speed between feeding, twisting, and winding parts at different stages, a core sheath composite with a length of meters was continuously produced CNT@nylon Spiral fibers. This fiber structure is uniform, has excellent flexibility and weaving ability, and the spiral structure is not damaged during the weaving process.

This work constructed a core sheath composite fiber structure. Among them, CNTs that play a driving role are distributed in the sheath layer, while inert polymer fibers located in the fiber core play a role in reducing the amount of expensive CNTs used. Research has found that those with a core-shell structure CNT@nylon Composite fibers provide a larger specific surface area and shorter migration paths for electrochemical ions, which facilitates more ion implantation and faster migration within the fibers, CNT@nylon The driving force of composite biomimetic muscle fibers can reach 26.4%.

Based on biomimetic muscle fibers, this study designed active deformable fabrics that can work stably in air environments. Research has shown that biomimetic muscle fibers and auxiliary fibers are woven parallel on flexible fabrics as working electrodes and counter electrodes, respectively. In order to prevent short circuits between the two electrodes during fabric deformation, the two fiber electrodes are woven in a staggered pattern. The micro pore structure within and between fibers in the fabric plays a role in adsorbing and stabilizing the electrolyte. Research has found that when a voltage is applied between the working electrode and the counter electrode, the ions in the electrolyte in the fabric migrate into the CNT layer of the working electrode, thereby causing CNT@nylon The fibers are driven by contraction. Researchers woven multiple sets of fiber electrode pairs into the fabric and found that each set of electrode pairs can be individually controlled or coordinated to control the operation of different electrode pairs. Therefore, the fabric can undergo both overall shrinkage and local deformation, with a high degree of deformation freedom.

Furthermore, this study encapsulated the electrochemically driven active deformation fabric and evaluated its application prospects as a wearable assistance fabric. The deformed fabric encapsulated by transparent flexible film has high flexibility and no electrolyte leakage. When working on the volunteer arm, it undergoes significant contraction with the application of voltage, and there is almost no temperature difference between the fabric and the arm during the working process. This indicates that the electrochemically deformed fabric has the characteristics of working in the air, flexible structure, programmable motion mode, and no heat generation, and is expected to become a candidate material for the next generation of wearable devices.



As a supplementary cover article, the relevant research results were published in ACS Nano under the title of Knittable Electrical Yarn Muscle for Morphing Textiles. The research work has received support from the National Natural Science Foundation of China, the National Key Research and Development Program, and the China Postdoctoral Science Foundation.



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