Optimized Design and Evaluation of Flexible Capacitive Sensors for Pressure and Temperature Sensing

This paper presents a flexible capacitive pressure sensor suitable for wearable applications. The sensor's dielectric layer is composed of PDMS with a micro-porous structure. When pressure is applied to the electrodes, the internal pores of this microstructure close, enabling effective external pressure sensing. We utilized screen meshes of 60-80, 80-100, 100-120, and over 120 mesh to sieve sacrificial particles (KCL) and achieve the desired pore sizes. Our analysis within a pressure range of 0.5-19N revealed improved sensitivity, reproducibility, and acceptable relative nonlinearity error of the sensors. Furthermore, the diverse incorporation step sequences and varying concentrations of the thermochromic material during the preparation process facilitate the sensor's ability to exhibit color changes that accurately reflect and monitor ambient temperature fluctuations. This enhancement ensures the sensor's effectiveness in providing valuable temperature data in various applications. The simplicity, ease of manufacture, and versatility of the sensor position it as a promising candidate for applications in electronic skin, health monitoring, and motion tracking.