Pruney fingers-inspired highly stretchable and sensitive piezoresistive fibers with isotropic wrinkles and robust interfaces

Song Chen, Junyun Li, Haizhou Liu, Wei Shi, Zefei Peng and Lan Liu*

Abstract

Scalable construction of robust and isotropic wrinkles on fiber surface is crucial for the development of highly sensitive piezoresistive fibers, which still remains a challenge. Herein, inspired by the typical morphology and formation of pruney fingers, we develop a novel core–shell “pruney fiber” with both isotropic wrinkles and robust interfaces via a scalable and facile fabrication strategy. Briefly, the robust isotropic wrinkles are constructed through the core thermoplastic polyurethane (TPU) molecular chain’s constriction and the sheath pyrrole monomer’ synergistic interfacial polymerization. As a result, the robust interfaces enable the pruney fiber high stabilities under a remark stretchability (200%). Two as-prepared pruney fibers are overlapped vertically for piezoresistive sensing. Owe to the interlocking of the surface isotropic wrinkles, the piezoresistive fibers show high sensitivity (0.15 kPa^-1), fast response time (47 ms), low detection limit (0.2 g), and high stability. For practical applications, the piezoresistive fibers can be easily weaved and integrated into a smart glove for wearable sensors and human–machine interfaces (HMI). At last, the novel structure and its unique scalable developing process would pave a new way in stable surface structure engineering on variable surface in the future.

文章链接：

https://doi.org/10.1016/j.cej.2021.133005