Compressible and Electrically Conducting Fibers for Large‐Area Sensing of Pressures

Abstract

Flexible pressure sensors offer a wide application range in health monitoring and human-machine interaction. However, their implementation in functional textiles and wearable electronics is limited because existing devices are usually small, 0D elements, and pressure localization is only achieved through arrays of numerous sensors. Fiber-based solutions are easier to integrate and electrically address, yet still suffer from limited performance and functionality. An asymmetric cross-sectional design of compressible multimaterial fibers is demonstrated for the detection, quantification, and localization of kPa-scale pressures over m 2 -size surfaces. The scalable thermal drawing technique is employed to coprocess polymer composite electrodes within a soft thermoplastic elastomer support into long fibers with customizable architectures. Thanks to advanced mechanical analysis, the fiber microstructure can be tailored to respond in a predictable and reversible fashion to different pressure ranges and locations. The functionalization of large, flexible surfaces with the 1D sensors is demonstrated by measuring pressures on a gymnastic mat for the monitoring of body position, posture, and motion.

Textile Technology for Soft Robotic and Autonomous Garments

“…Leber and colleagues built upon this concept and used the thermal drawing process to create resistive pressure sensing fibers wherein the pressures and their generalized magnitudes could be localized. [ 408 ] They created a unique architecture from SEBS as a deformable shell with highly structured internal geometries of carbon‐black‐loaded polyethylene as conductors. Depending on the amount of pressure applied, a corresponding number of conductors would come into contact with each other, enabling pressure sensing, while the position of the pressure input would reduce the total resistance linearly.…”

Microstructured Biodegradable Fibers for Advanced Control Delivery

“…Here, we demonstrate the scalable fabrication of microstructured biodegradable fibers with multiple reservoirs of arbitrary size and position, spanning the entire fiber length, from which control release of unprecedented complexity can be achieved. We rely on the thermal drawing process, a versatile fiber‐processing approach particularly suited to fabricate complex multimaterial architectures 18–30. For the first time, we identified various grades of biodegradable amorphous thermoplastic polymers poly( d , l ‐lactic‐ co ‐glycolic acid) (PLGA) with the proper thermomechanical and rheological properties to be thermally drawn and maintain complex architectures and high mechanical strength.…”

Self-powered multifunctional sensing based on super-elastic fibers by soluble-core thermal drawing

“…It has enabled a wealth of functionalities, including material engineering [9][10][11] , optical sensing 12,13 , neural sensing 14,15 , thermal detection 16,17 , chemical sensing 18,19 , acoustic emission 20,21 , and many more 22 . Prospectively, such functional fibers can be a promising candidate for soft electronics [23][24][25][26][27] with the consideration of their unique advantages of high dynamic bending elasticity 28 , stretchability 29 , and high mechanic strength 30,31 . Despite the myriad of available working principles which the soft electronics are mainly developed from such as piezoresistive effect 32,33 , capacitance variation effect 34 , piezoelectric effect 35 etc., an emerging technique triboelectric nanogenerator (TENG) 36 utilizing the triboelectrification effect has enabled wide spread applications in self-powered sensors 37,38 .…”