An All‐Nanofiber‐Based, Breathable, Ultralight Electronic Skin for Monitoring Physiological Signals

Electronic skins (e-skins) are a promising design paradigm for health care systems and human-machine interactions. Piezoresistive sensors made with simple structures, high sensitivity, mass production methods, light weight, and comfort for long-term wearing and physiological signal monitoring remain a challenge and are urgently desirable. Here, a breathable and lightweight all-nanofiber piezoresistive (ANFP) sensor is presented, which is composed of three layers of electrospun nanofibers (NFs). A specific interpenetrating network of conductive polyvinylpyrrolidone NFs coated by polypyrrole (PVP@PPy) and insulating polyacrylonitrile NFs is constructed by controlling the vapor growth position of PPy to enhance the sensitivity. The ANFP sensor can achieve the real-time monitoring of multiple parts of physiological signals, and a wireless detection system is designed for the online monitoring of human pulses. The NF network endows excellent breathability and heat dissipation to the ANFP sensors during practical application, which ensures comfort and device stability during long-term wearing. Finally, a pressure sensing array with 5 x 5 pixels is fabricated to demonstrate the potential applications in spatial pressure detection. This work provides a viable strategy to improve the wearability of e-skins, which can promote health care and human-machine interaction applications.