Flexible Linkage Design of Composite Dielectric Layer for High-Performance Capacitive Pressure Sensor

Abstract

A trade-off exists between flexible capacitive pressure sensors’ sensitivity and detection range. Existing strategies to improve the sensitivity of flexible capacitive pressure sensors by increasing microstructures and using composite materials to enhance dielectric properties are usually only effective in the low-pressure range. Limited material compressibility and dielectric properties are key factors limiting device performance. This paper proposes a composite dielectric layer based on the flexible linkage architecture (FLA), which is designed and directly manufactured using direct ink writing (DIW) 3D printing technology. Adding conductive carbon black (CB) particles increases the composite material’s relative dielectric constant. It works synergistically with the FLA dielectric layer to improve sensor’s sensing performance. With systematical optimization, the sensor exhibits high sensitivity over a wide pressure range, from 2.557 kPa^–1 within 0–2 to 0.034 kPa^–1 within 200–450 kPa. As a demonstration, sensors are utilized to monitor the movement of the robotic hand.