Design and Testing of Flexible Pressure and Temperature Sensing Capacitive Sensors

This paper presents a flexible capacitive pressure sensor suitable for wearable applications. Utilizing polydimethylsiloxane (PDMS) with a micro-porous structure as the dielectric layer of the sensor, the internal pores of this microstructure close when pressure is applied to one or both ends of the electrodes. This closure effectively senses external pressure. The screen mesh of 60-80, 80-120, and over 120 mesh were used in the preparation process to sieve sacrificial particles (KCL) and obtain the desired particle size for creating pores. The sensitivity, repeatability, relative nonlinearity error of the sensors, and the impact of the addition of thermochromic materials on color changes with temperature were analyzed within a pressure range of 0.5-19N. It was observed that the sensitivity increased with the introduction of a micro-porous structure into the dielectric layer, and it exhibited repeatability. Moreover, the structure is simple, easy to manufacture, and have a wide range of important applications in electronic skin, health detection and motion monitoring.