Flexible Piezoresistive Pressure Sensor Based on AgNWs-Gr Sponge Dielectric Layer for Tactile Monitoring

To develop a piezoresistive flexible pressure sensor with high sensitivity and stability, this research uses sponge as the substrate and silver nanowires (AgNWs) and graphene (Gr) as the conductive materials, prepares a piezoresistive flexible pressure sensor based on AgNWs-Gr sponge dielectric layer by the “sandwich-like” encapsulation, and tests its performance. The results show that the added AgNWs-Gr can effectively improve the sensitivity of the sensor while maintaining the porous structure of the sponge. The piezoresistive flexible pressure sensor based on AgNWs-Gr sponge dielectric layer has the highest sensitivity when the concentration of AgNWs-Gr solution is 5%. The sensitivity can reach 0.4373 kPa⁻¹ at pressures ranging from 0 to 3 kPa, and it has rapid response and recovery, as well as good repeatability and stability. In terms of the excellent sensing performance of the sensor, we perform high-pressure and low-pressure tests by placing light and heavy objects on the sensor, swallowing tests by placing it at the thyroid notch, and pressure monitoring tests by finger pressing. The results show that the sensor can accurately monitor swallowing, finger pressing, and real-time pressure changes at both high and low pressures and has great potential in the fields of intelligent robotics, wearable devices, robotic skin, and medical detection.