High-performance flexible pressure sensor based on ordered double-level nanopillar array films: Design, development, and modeling

Abstract

To improve the sensitivity and broaden the range of flexible pressure sensors, we proposed a high-performance flexible pressure sensor based on ordered double-level nanopillar array films. In this work, polypyrrole/multi-walled carbon nanotube/polyurethane (PPy/MWCNT/PU) conductive films with double-level nanopillar array microstructures were prepared by continuously adjusting the oxidation and pore expansion parameters of a porous anodic alumina template (AAO), where the high pillar height was 1243.0 ± 7.0 nm, and the low pillar height was 868.0 ± 4.70 nm. We studied the influence of the structural characteristics of ordered double-level nanopillar array conductive films and a flexible pressure sensor on the sensing performance using finite element simulations, the establishment of sensing mechanism, and sensor performance measurements. The results showed that the pressure was positively correlated with the change rate of strain and the surface microstructure contact area of the ordered double-level nanopillar array films. The sensor sensitivity reached 208.353 kPa−1, and its range was extended by 267%. In addition, the sensor, which could monitor vocalization, drinking pulse and finger movements, could be used in a wide range of applications, including wearable medical monitoring and smart sign language textiles.