Superhydrophobic Ultraflexible Triple-Network Graphene/Polyorganosiloxane Aerogels for a High-Performance Multifunctional Temperature/Strain/Pressure Sensing Array

Recently, many efforts have been made to develop various smart sensors. However, achieving flexible multifunctional sensors combining excellent sensing of temperature, strain, and pressure with a single material is still challenging. Here, we report unprecedented superhydrophobic ultraflexible reduced graphene oxide (rGO)/polyorganosiloxane aerogels and high-performance multifunctional temperature/strain/pressure sensors based on these aerogels. GO nanosheets are first cross-linked and reduced with (3-aminopropyl)triethoxysilane (APTES) to obtain APTES-modified rGO aerogels, which are then further covalently cross-linked with polyvinylmethyldimethoxysilane polymers and vinylmethyldimethoxysilane via copolycondensation to afford rGO/polyorganosiloxane aerogels. The resulting aerogels exhibit a coralline-like triple-network nanostructure consisting of rGO nanosheets, polyvinyl-poly(methylsiloxane), and poly(vinylmethylsiloxane) that are cross-linked with each other. The aerogels combine superhydrophobicity, high compressibility, high bendability, superelasticity, excellent machinability, and temperature-, strain-, and pressure-sensitive conductivity, which is a combination not observed with traditional materials. In addition, an rGO/polyorganosiloxane aerogel-based flexible multifunctional sensing array combining sensing of temperature (20–100 °C), strain (in the wide range of 0.1–80%), and pressure (in the wide range of 10 Pa to 110 kPa) with high sensitivity and high durability against compression, bending, and humidity has been demonstrated for the first time.