A highly sensitive flexible pressure sensor based on nanoarchitectonics with biomimetic petal structure

Abstract

Flexible capacitive pressure sensors play a crucial role in the field of wearable electronics. Presently, most flexible capacitive pressure sensors choose polydimethylsiloxane (PDMS) as the material of the dielectric layer, because of its excellent elasticity and biocompatibility. However, these flexible pressure sensors suffer from low sensitivity because the uniform dielectric layer has a fixed relative dielectric constant (RDC). Researchers have developed microstructured dielectric layers to achieve pressure-induced changable RDC, so as to enhance the sensor sensitivity. However, the typical process of fabricating microstructures is complex, and the enhancement in sensor sensitivity is limited. Here, we report a simple and effective biomimetic strategy to enhance the sensor sensitivity. First, the petal microstructure is replicated with PDMS. Then, a 180 nm zinc oxide (ZnO) layer is sputtered to form a pressure sensitive layer, which will possess a pressure sensitive and changeable RDC. The as-fabricated biomimetic-petal-microstructure sensor (BPMS) achieves an average sensitivity of up to 0.28 kPa^− 1 (0–2 kPa), a fast response time of 0.1 s, and good stability over 1,000 cycles of operations, showing a broad application prospect in wearable electronics.