Fabrication of a pressure sensor using 3D printed light-cured piezoelectric composites

A 0–3 piezoelectric composite material composed of piezoelectric ceramic particles and polymers combines the performance advantages of both components and has broad prospects for applications in piezoelectric pressure sensors, and 3D printing technology provides a good solution for fabricating complex structures of piezoelectric pressure sensors. However, the current research on stereolithography 3D printing for fabricating piezoelectric appliances focuses on the printing of photosensitive piezoelectric composite slurry, and the piezoelectric output of piezoelectric composites prepared with slurry is low due to the low solid content of the slurry, and an inability to stably store the slurry for a prolonged duration. To improve the piezoelectric output performance, this study investigated the material system and structural design of stereolithography 3D printing of piezoelectric composites based on the dispersion stability of the piezoelectric ceramic paste. The results revealed that 72 wt% paste prepared with oleic acid-grafted and modified piezoelectric ceramic particles has good stability, and the piezoelectric voltage constant of the piezoelectric composites fabricated with paste was 220.2 × 10−3Vm‧N−1, and the piezoelectric sensitivity of the piezoelectric composite after topology optimization could reach 30 mV·kPa−1. A conformal pressure sensor prepared using photocuring 3D printing technology can effectively detect the compressive stress of curved surfaces.