Contact-dominated localized electric-displacement-field-enhanced pressure sensing

Abstract

Pressure sensors, especially the typical capacitive sensors that feature low power consumption, have drawn considerable interest in emerging and rapidly growing fields such as flexible electronics and humanoid robots, but often suffer from limited performance. Here, we report a contact-dominated design for capacitive pressure sensors to dramatically improve the sensing response and linearity over a broad pressure range. This design is implemented by utilizing hierarchical microstructured electrodes made of robust conductive composites with metallic coverage and layered dielectrics with high unit-area capacitance to realize localized electric-displacement-field-enhanced capacitance change. We demonstrate a significant improvement in pressure response beyond 3000 and a sensing range exceeding 1 MPa, particularly with a near-linear response (optimized R2 of 0.9998) and high sensitivity of 9.22 kPa−1 in a wide pressure range of 0–100 kPa. Moreover, we present that the integration of the contact-dominated sensor with floating-gate low-dimensional semiconductor transistors can provide a transduced electrical response of ~4 × 105 at a low operating voltage of 2.66 V due to the greatly enhanced pressure response. We also demonstrate the potential applications of our sensor in fluid physical property evaluation and precise dynamic control of a robotic arm for manipulation tasks. This study proposes a contact-dominated, field-enhanced design for capacitive sensors, achieving high response, strong linearity, and high sensitivity over a broad range, demonstrating great potential for functionalized flexible electronics and artificial intelligence robotic applications