Flexible Piezoresistive Pressure Sensor Based on SLA 3D Printing Assisted Manufacturing Surface Microstructure

Microstructure plays an important role in improving the performance of flexible pressure sensors. Microstructure parameter design is an effective strategy to improve the performance of pressure sensors. However, the traditional microstructure manufacturing has the problems like high manufacturing cost, cumbersome manufacturing process and simple structure, which restricts the development of flexible pressure sensors. In this paper, a method based on SLA 3D printing mold to prepare flexible pressure sensors with designed microstructure is proposed using PDMS as the substrate, which lowers the difficulty of mold preparation and greatly improves the flexibility in microstructure design. Especially, the conical microstructure with the spacing of 0.2 mm and the aspect ratio of 1:1 has the best performance, like high sensitivity (11.67 kPa -1 at 0-5.2 kPa, 0.357 kPa -1 at 5.2-200 kPa), wide detection range (>200 kPa), rapid response/recovery time (26 ms/17 ms) and excellent long-term stability (4000 cycles). Finally, the sensor is demonstrated in human signal monitoring and finger behavior recognition, indicating its wide application possibility.