Supersensitive natural rubber-based piezoresistive pressure sensor with hierarchical sandwich structure

The burgeoning fields of wearable devices, medical monitoring and human-motion detection have spurred the interest in flexible piezoresistive pressure sensors, which in turn have raised concerns about the sustainable development of flexible electronics. Herein, natural rubber was utilized as a flexible substrate to fabricate a high-performance piezoresistive pressure sensor with a hierarchical sandwich structure via a filtration-template method. The sensor exhibited excellent overall sensing performances (sensitivity of 96.0 kPa^-1 and 17.97°^-1, response/recovery time of 20/53 ms and 20 000 loading-unloading cycles at 0-95% resistance change). Meanwhile, the sensor was successfully applied for human motion detection, health monitoring and Morse code signal transmission. Owing to the superhydrophobicity of the sensitive interlayer and porous protective layer, the sensor also exhibited potential for underwater sensing. Our findings conceivably stand out as a new strategy to prepare environmentally friendly and high-performance piezoresistive pressure sensors and will promote the sustainable development and application of flexible electronics.