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

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.