Biomimetic Wearable Flexible Pressure Sensor With Multilevel Microstructured Piezoresistive Layer

Bionics has given a new impetus to the development of flexible sensors. This paper shows the scheme of designing flexible resistance pressure sensor with high performance by using multi-level microstructure on the surface of natural hosta leaf. A conductive network composed of multi-walled carbon nanotubes (MWCNTs) was formed on the surface of leaves by spraying method, and the piezoresistive layer was fabricated by coating polydimethylsiloxane (PDMS) to replicate multi-level microstructure. The biomimetic multi-level microstructure formed by placing the leaf veins of two piezoresistive layers in an special intersecting "#" shape ensures the stability and high sensing performance of the designed sensor, such as high sensitivity of 1.619 kPa-1, wide pressure detection range (>100 kPa), fast response time, low detection limit and high stability. The sensor shows its practical application in human joint motion, micro vibration detection and tactile feedback for robot grasping, which are potentially useful in wearable devices and intelligent prosthetics.