Tunable and Nacre‐Mimetic Multifunctional Electronic Skins for Highly Stretchable Contact‐Noncontact Sensing

Electronic skins (e‐skins) have attracted great attention for their applications in disease diagnostics, soft robots, and human–machine interaction. The integration of high sensitivity, low detection limit, large stretchability, and multiple stimulus response capacity into a single e‐skin remains an enormous challenge. Herein, inspired by the structure of nacre, an ultra‐stretchable and multifunctional e‐skin with tunable strain detection range based on nacre‐mimetic multi‐layered silver nanowires /reduced graphene oxide /thermoplastic polyurethane mats is fabricated. The e‐skin possesses extraordinary strain response performance with a tunable detection range (50 to 200% strain), an ultralow response limit (0.1% strain), a high sensitivity (gauge factor up to 1902.5), a fast response time (20 ms), and an excellent stability (stretching/releasing test of 11 000 cycles). These excellent response behaviors enable the e‐skin to accurately monitor full‐range human body motions. Additionally, the e‐skin can detect relative humidity quickly and sensitively through a reversible physical adsorption/desorption of water vapor, and the assembled e‐skin array exhibits excellent performance in noncontact sensing. The tunable and multifunctional e‐skins show promising applications in motion monitoring and contact‐noncontact human machine interaction. For contact sensing, the nacre‐mimetic electronic skin possesses ultra‐low detection limit, super‐fast response time, high sensitivity, and excellent durability with a tunable sensing range. For noncontact sensing, the electronic skin exhibits precise sensing behaviors to the humidity of human breath and fingers, which shows potential applications in human motion monitoring and contact‐noncontact sensing systems.