Ultrahigh sensitivity and wide strain range of porous pressure sensor based on binary conductive fillers by in-situ polymerization

High-performance wearable electronics show great potential in the soft robotics, artificial intelligence, human–machine interaction, health care, etc. Due to the wide application in heart rate detection, voice monitoring, and sports data collection, the pressure sensor has grasped a lot of attention. However, poor cycle stability, low sensitivity and narrow working pressure range hinder the further development of the pressure sensors. To solve the above mentioned problems, a polyurethane-based conductive sponge is prepared via silver nanoparticle coating after the in-situ synthesis of poly(3,4-ethylene dioxythiophene) on the backbones of polyurethane foam. The flexible pressure sensor exhibits excellent performance, including ultrahigh sensitivity (3.039 kPa−1), wide working range (0–35 kPa), frequency-independent performance, reliable repeatability (~ 1000 cycles), rapid and stable response. Finally, we successfully demonstrated these flexible sensors in detecting tiny physiological activities and human motions. All the results demonstrate that the the polyurethane-based pressure sensor is a promising candidate for soft electronics and healthcare monitoring.