A flexible dual-function capacitive sensor enhanced by loop-patterned fibrous electrode and doped dielectric pillars for spatial perception

The integrated perception capable of detecting and monitoring varieties of activities is one of the ultimate purposes of wearable electronics and intelligent robots. Limited by the space occupation, it lacks practical feasibility to stack multiple types of single sensors on each other. Herein, a high-sensitivity dual-function capacitive sensor with proximity sensing and pressure sensing is proposed. The fringing electric field can be confined in the proximity-sensitive area by fibrous loop-patterned electrode, leading to more stolen charges when object approaching and thus a high proximity sensitivity. The high-permittivity doped structured dielectric layer reduces the compressive stiffness and enhances the rate of compression-caused increase in the equivalent relative permittivity of the dielectric layer, resulting in a larger increase in capacitance and thus a high pressure sensitivity. The electrodes and dielectric layer together compose the capacitor and act as the sensor without taking up additional space. The decoupling of proximity-sensing and pressure-sensing modes can be achieved by decrease or increase in capacitance. Combined with array distribution and sequential scanning, the sensors can be used for detection of motion trajectory, contour recognition, and pressure distribution.