Topology-optimized flexible capacitive pressure sensors suitable for medium-pressure range

Abstract Numerous flexible capacitive pressure sensors (FCPSs) designed for low-pressure range perform highly sensitive sensing over a wide detection range. However, these sensors are primarily based on inspiration, and large pressure applications have yet to be explored. In this paper, we propose for the first time the stiffness topology optimization of hyperelastic dielectrics by analyzing the working mechanism and target sensing characteristics. The feasibility of using topological dielectric as a dielectric layer for FCPSs is evaluated through a combined analysis using ABAQUS and COMSOL. Three different volume fractions (f *) FCPSs (f *= 0.35,0.4,0.5) are manufactured utilizing 3D printing. The FCPSs exhibited high sensitivity at external pressure values of 7.06 kPa (f *= 0.35), 8.71 kPa (f *= 0.4), and 18.9 kPa (f *= 0.5), respectively, and the highest sensitivity reached 1.29 kPa-1 (f *= 0.35). In addition, when f * =0.35, FCPSs exhibiting high repeatability over 6000 cycles in 40 kPa, a relatively wide detection range (60 kPa) and high stability at different pressures (5-60kPa) and temperatures (15-60℃). Lastly, the high performance of FCPSs is further illustrated through motion monitoring of three different joints, collision monitoring of a 3D printer, and testing on a robotic car, indicating their application prospects.