Biomass carbon nanosphere/PANI wrapped polyurethane foam for multi-scale piezoresistive flexible pressure sensor with high stability and sensitivity

The polyurethane foam-based flexible piezoresistive sensors have demonstrated significant potential in a wide range of applications. However, the development and application of these sensors are limited by their stability and sensitivity. Herein, a kind of polyurethane foam-based flexible piezoresistive sensor is developed by wrapping biomass carbon nanospheres and polyaniline onto the network of the polyurethane foam, where the aniline is in-situ polymerized onto the polyurethane foam network and the biomass carbon nanospheres are acquired via the carbonization cuttlefish ink. Thanks to the intricately designed multi-scale structures on the threedimensional framework of polyurethane foam, the fabricated sensors demonstrate a remarkable sensitivity of 170.29 kPa- 1 within the pressure range of 40-75 kPa. The sensors also display a short response time of 130 ms and a rapid recovery time of 85 ms. Furthermore, the strong adhesion between the conductive material and the substrate leads to excellent stability of the sensor which last for over 10,000 cycles. With these properties, the sensor shows good performances when applied to motion capture and health monitoring.