High-performance and superhydrophobic piezoresistive pressure sensor based on mountain ridge-like microstructure by silver nanoparticles and reduced graphene oxide

Ingenious microstructure design is crucial for piezoresistive pressure sensor to achieve excellent sensing performances and water repellency. Herein, we propose a new strategy to prepare high-performance polydimethylsiloxane (PDMS) sponge-based piezoresistive pressure sensor with superhydrophobicity. The silver nanoparticles and reduced graphene oxide on the skeleton surface of PDMS sponge jointly constructed mountain ridge-like microstructure and endowed the sensor with conductive network. The sensor exhibited high sensitivity, wide detection range, fast response and exceptional repeatability (4,000 loading–unloading cycles) and was applied for detecting human motions and daily scenarios. Owing to the hierarchical microstructure and the surface modification by 1H,1H,2H,2H-perfluorooctyltriethoxysilane, the sensor showed a high water contact angle of 156°, and the response signal kept stable even being sprayed by water. The prepared high-performance and superhydrophobic piezoresistive pressure sensor in this work has great potential in wearable electronics, healthcare monitoring and smart robot.