Microgroove-engineered hybrid pressure sensor for wide-range and fast tactile sensing

The simultaneous improvement in sensitivity, response speed, and operating range of flexible pressure sensors is crucial for their applications in human-computer interaction, health monitoring, and robotic perception. Inspired by the microgroove structure of scorpion slit sensilla, a biomimetic pressure sensor based on a rigid-flexible hybrid design strategy is proposed in this study. This sensor is composed of a flexible layer of polydimethylsiloxane (PDMS) and a rigid layer of spring steel. A microgroove array template is fabricated on a zirconia ceramic substrate using a femtosecond laser, and a biomimetic microgroove array is formed on the PDMS surface via the template replication method. Silver nanoparticles are sputtered onto the surface as the conductive layer. Experimental results show that the sensor has a high sensitivity of 1.50 ± 0.04 kPa^-1, a wide operating range of 0.2 kPa to 140 kPa, an average linearity (R²) as high as 0.995 within the 0.2 kPa to 20 kPa range, a response time of 45 ± 4 ms, and a recovery time of 40 ± 3 ms. By integrating the sensor into the sole of a quadruped robot and combining it with a Bluetooth wireless transmission module and machine learning algorithms, the system achieves high-precision identification of four types of geological environments.