Highly Stretchable,\nConductive, Adhesive, and Self-Powered\nIonogel Sensor for Human Motion Detection, Signal Transmission, and\nTraffic Monitoring

Abstract

Distinguished from traditional power sources such as\nbatteries\nand capacitors, triboelectric nanogenerators have higher freedom of\nmaterial selection and application flexibility and thus can fulfill\nthe needs of flexible self-supplied electronic devices for advanced\ne-skin, human–computer interaction, and sensing. Here, a flexible\n(1100% of elongation at break, 0.2 MPa of breaking strength), highly\nconductive and adhesive (120 kPa), and environmentally stable ionogel\nwas fabricated by introducing ionic liquids into a physical cross-linking\npolymer framework. The ionic liquid built a nonaqueous solvent system\nthat made the ionogel environmentally stable. The introduction of\namphiphilic ions both improved the mechanical properties of the polymer\nnetwork and acted as ion channels to enhance the mobility of the ionic\nliquid and thus the electrical conductivity. Meanwhile, dynamic hydrogen\nbonding and dipole–dipole interaction made the ionogel have\ngood adhesion properties. The ionogel can be applied as a flexible\nsensor for strain and pressure monitoring, and more importantly, the\nassembly of the ionogel with silicone rubber elastomer films into\na sandwich-structured triboelectric nanogenerator enabled its application\nin scenarios such as self-supplied messaging and all-weather traffic\nmonitoring, and it can also provide wired and wireless signal outputs\nwith fast response (∼0.04 s). This work provides a direction\nfor the application of gel-based electronic devices in the fields\nof intelligent human–computer interaction, information transfer,\nhealth monitoring, and traffic detection.