An Intrinsically Stretchable and Ultrasensitive Nanofiber-Based Resistive Pressure Sensor for Wearable Electronics
To date, most skin-like pressure sensors largely depend on the conventional lithography technique for fabricating microstructures, limited by chemical-intensive with time-consuming manufacturing processes that have limited the implementation scalability. Herein, we present the nano-resistors alongside the fibrous interlocked microstructures (FIMs) concept integrated by a one-step electrospinning technique, which is a cost-effective, lithographic-free approach with large-area expandability to fabricate skin-inspired resistant-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), whereas the dielectric SEBS nanofiber is 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 in a low-pressure area (<0.06 kPa), 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 carried out by integration with an RGB-LED wristband and garments, and for monitoring human physiological signals, thereby endowing our ESSCN with broader potential applications in versatile electronic skin and human–machine interfaces.