Investigating capacitive force sensors with 3D printed flexible structures as dielectric layers

Abstract The utilization of a three dimension (3D) printing for the fabrication of micro-electromechanical system (MEMS) sensors presents various advantages including low cost, customization, simplicity, and speed. This study involved conducting mechanical and electrical analyses on three types of dielectric layer structures using the finite element method. Capacitive force sensors were produced through 3D printing using fused deposition modeling (FDM). The sensitivity and stiffness of the sensors were determined by measuring their capacitance and displacement changes under force using a self-made measurement system. The experimental results indicate that pre-heating the dielectric layer can reduce the hysteresis effects. In terms of more complex structures, stringing phenomena during the printing process can compromise the reliability of the sensor. A suitable dielectric layer structure can be designed based on the measurement range and sensitivity of the sensor. The results of this study demonstrate the potential for additive manufacturing to replace conventional MEMS processes in sensor production. With the advancement of FDM printing technology, it is increasingly feasible to apply 3D printing technology to sensor manufacturing in the future.