Wearable, washable piezoresistive pressure sensor based on polyurethane sponge coated with composite CNT/CB/TPU

Flexible pressure sensors are widely used in human health detection and human-machine interface interaction. In this paper, a 3D porous flexible pressure sensor based on carbon nanotubes (CNT)/carbon black (CB)/thermoplastic polyurethane (TPU)/polyurethane (PU) sponge is studied. This sensor exhibits good sensitivity, stability and washability. The sensing layer utilizes a conductive network formed by the synergistic effect of CNT and CB, providing excellent performance for the sensor. TPU functions as an adhesive, ensuring the bonding of the conductive material and providing washability to the sensor. Additionally, CB particles enhance the sensitivity of the sensor at low pressure range. The sensor demonstrates a response time of 119 ms, a recovery time of 59 ms, and maintains non-attenuating durability for more than 1000 cycles. This multi-functional pressure sensor can provide a new platform for the designing and developing wearable health monitoring devices, as well as an efficient human-machine interface.