Distribution optimization of micro-cone structures in the dielectric layer of a capacitive flexible pressure sensor

Abstract

Flexible capacitive pressure sensors have been attracting tremendous attention due to their potential applications in many fields, such as in intelligent electronics and wearable devices. Micro-structure designing of the dielectric layer is one of the key methods of improving the sensitivity of a sensor. In this paper, a method of structure distribution optimization for the micro-cone dielectric layer of a flexible capacitive pressure sensor is proposed. A mathematical model was developed during the study to quantify the distribution characteristics of the dielectric layer and predict the sensitivity of the sensor. By optimizing the structure distribution in the dielectric layer, the sensitivity of the capacitive sensor can be improved. The test results show that a sensor with an optimal structure distribution in the dielectric layer had a high sensitivity (1.43857 kPa−1) in a low pressure range (0–160 Pa), a low detection limit (∼1.96 Pa), a fast response time (166 ms), and good stability for 2500 cycles. Furthermore, the sensor demonstrated high sensitivity and good dynamic response in speech recognition and grasping experimental application tests.