Improving performance of AgNPs/PDA/TPU electrospun composite film based flexible pressure sensor by hot imprinted microstructure array

Highly sensitive sensors have attracted considerable attention in areas such as electronic skin, health monitoring and artificial intelligence. Herein, a simple and efficient approach was proposed to fabricate hierarchically structured flexible sensors. A common metal mesh was used as a template and its pattern was transferred to the surface of a composite film of silver nanoparticles (AgNPs) decorated polydopamine (PDA) and polyurethane (TPU) electrospun fibers by hot imprinting. The resulting film with a uniform convex microstructure array on the surface was used as the conductive sensing layer of the AgNPs/PDA/TPU sensor. The sensor exhibited a linear detection range increased from 15 kPa to 20 kPa compared to the control sensor without the microstructure. Furthermore, the sensitivity was improved from 8.13 kPa-1 to 10.44 kPa-1. The response time and recovery time of the sensor were determined to be 110 ms and 90 ms, respectively, and it maintained good stability at 10 kPa even after 1000 compression cycles. In addition, the sensor enabled real-time pressure signal detection for touch, joint movement and voice recognition, showing promising applications in health monitoring, pressure detection and human-machine interaction.