Self-Powered Ultra-Stretchable Organo-Hydrogel Sensors with Excellent Stability Based on a Solvent Replacement Strategy

Abstract

With the development of flexible wearable devices, conductive hydrogels have attracted widespread attention due to their unique properties. However, traditional conductive hydrogels often suffer from poor mechanical properties and environmental stability, greatly limiting their application areas. Herein, a dynamic hydrophobically associated organo-hydrogel network, which is composed of polymer chain backbone (acrylamide and lauryl methacrylate), dispersant (sodium dodecyl sulfate), conductive filler (lithium bis(trifluoromethyl)sulfonimide), and crosslinker (containing dynamic imine bonds) is constructed. Then, through a solvent replacement strategy of glycerol, the conductive organo-hydrogels are obtained with excellent mechanical properties (1.21 MPa strength, 12.87 MJ m⁻³ toughness, and 3501% ultra-stretching), outstanding environmental stability (work stably in a wide range from −20 to 60 °C), and room-temperature self-healing ability (self-healing efficiency over 90%). Based on these performances, they are used as the working electrode of the triboelectric nanogenerators, which endows the triboelectric nanogenerators with an output voltage of 127 V, a power density of 205 mW m⁻², and the ability to maintain a stable output over 10 000 cycles. A self-powered sensor is also constructed, which can realize the function of material recognition with the assistance of machine learning. This work will provide new ideas for the development of novel self-powered sensors.