An analytical model for flexible piezo-capacitive sensors with point-like patterned contacts

Capacitive flexible pressure sensors with patterned microstructures have attracted ever-increasing attention in the field of wearable electronics. However, there is still a lack of a reliable method for predicting the performance of flexible piezo-capacitive sensors, leading to difficulty for designing and evaluating microstructures. In this paper, we establish an analytical method for designing flexible capacitive sensors with point-like electrical field concentration and further derive an accurate expression for pyramid electrodes by combining high throughput finite element simulations with machine learning. Besides, we have designed and fabricated a high-performance pressure sensor with the simulation and analysis based on our model. A thin high- k dielectric layer with rough surface is selected as the dielectric layer, yielding a high sensitivity of 0.031 kPa –1 to 0.115 kPa –1 in an ultra-wide pressure range from 3.4 Pa to 2.5 MPa. • We established a general analytical model to calculate capacitance of piezo-capacitive sensors with micro-contacts. • We combined physics, machine learning, and simulation methods to derive the precise parameters of the analytical model. • Guided by this analytical model, we fabricated a highly sensitive sensor with a broad pressure range.