High sensitivity SnSe2/MWCNTs flexible pressure sensors based on a lotus leaf biomimetic microstructure for electronic skin

Abstract

Flexible pressure sensors have been extensively implemented in electronic skin, intelligent robots and human–computer interactions because of their excellent mechanical flexibility. However, there are still serious challenges in achieving highly sensitive detection of pressure changes in the low-pressure range. In order to further expand the application of flexible pressure sensors and improve the sensing performance, we propose a new bionic strategy. Inspired by the surface structure of lotus leaves, SnSe₂/MWCNTs pressure sensors with geometrical prickly microstructures were prepared. Multilayer piezoresistive pressure sensors are composed of a micropatterned polydimethylsiloxane (PDMS) substrate, a SnSe₂/MWCNTs sensitive film and a flexible interfinger electrode. The high-performance SnSe₂/MWCNTs pressure sensor features a wide pressure range (0–80 kPa), high sensitivity (165 kPa⁻¹), and fast response/recovery time (88 ms/58 ms). SnSe₂/MWCNTs pressure sensors can be used to detect human movement and health signals, further demonstrating their excellent response speed, detection accuracy and stability. In addition, a 4 × 4 sensor array was developed to detect the pressure distribution of objects with different shapes, which realized the accurate detection of the shape and pressure distribution of objects, and expanded the application of flexible pressure sensors in the field of electronic skin.