An intrinsically stretchable and ultrasensitive nanofiber-based resistive pressure sensor for wearable electronics

Abstract

To date, most skin-like pressure sensors largely depend on the conventional lithography technique for fabricating microstructures, limited by chemical-intensive and time-consuming manufacturing processes, which have limited the implementation scalability. Herein, we present the nano-resistor alongside fibrous interlocked microstructure (FIM) concept integrating a one-step electrospinning technique, which is a cost-effective, lithographic-free approach with large-scale expandability to fabricate skin-inspired resistive-type pressure sensors with ultrahigh performance and lightweight characteristics. The unique elastic sandwich-structured conducting nanofiber (ESSCN) configuration comprises poly(styrene-block-ethylene-ran-butylene-block-styrene) (SEBS) natural rubber and silver nanoparticles (AgNPs), while dielectric SEBS nanofibers are employed as the middle layer, sandwiched by two SEBS/AgNP electrodes at the top and bottom for packaging. The FIM endows the obtained pressure sensors with superior performance, including an ultrahigh sensitivity of 71.07 kPa⁻¹ under a small applied pressure (<0.06 kPa), a rapid response time (<2 ms), highly reproducible stability (>5000 cycles) with excellent off/on switching behaviors, and mechanical stimuli sensing (pressure, strain, and bending). As a proof-of-concept demonstration, the sensors can be implemented through integration with an RGB-LED wristband and garments for monitoring human physiological signals, thereby endowing our ESSCN with broader potential applications in versatile electronic skin and human–machine interfaces.