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

Flexible capacitive 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.