Microstructure-Based Interfacial Tuning Mechanism of Capacitive Pressure Sensors for Electronic Skin

In order to investigate the interfacial tuning mechanism of electronic skin (e-skin), several models of the capacitive pressure sensors (CPS) with different microstructures and several sizes of microstructures are constructed through finite element analysis method. The simulative pressure response, the sensitivity, and the linearity of the designed CPS show that the sensor with micropyramids has the best performance in all the designed models. The corresponding theoretically predicted sensitivity is as high as 6.3 × 10−7 fF/Pa, which is about 49 times higher than that without any microstructure. Additionally, these further simulative results show that the smaller the ratios of L/H of pyramid, the better the sensitivity but the worse the linearity. When the ratio of L/H of pyramid is about 2, the sensitivity and the linearity could reach a balance point. The simulative results evidently provide the important theoretically directive significance for the further development of e-skin.