3D printing for capacitive flexible pressure sensors of small pressure high sensitivity with microdome-labyrinth structure

Capacitive flexible pressure sensors have excellent sensing characteristics such as ductility and high sensitivity, and are capable of accurately detecting small pressures generated by human movement and human–computer interaction. However, small pressure sensors fabricated using most conventional preparation methods (e.g. stencil molding) do not provide high enough resolution for small pressure measurements. Therefore, in this paper, capacitive flexible pressure sensors that can be applied to motion signal detection and motion sensing are prepared using digital light processing printing technology. Elastomers with microdome and labyrinth composite structures are prepared using polyurethane acrylate materials. At the same time, the sensor is capable of detecting minute pressures as low as 1 pa and has a wide detection range with a sensitivity S of 0.037 kPa⁻¹ in the 0–20 kPa stress range and 0.007 kPa⁻¹ in the 300–400 kPa stress range.