Synergistic control of engineered nanostructures toward sensitivity and reliability of a flexible piezoresistive pressure sensor

Abstract

Flexible pressure sensors are among the most important flexible electronics used in various electronic skin applications, including artificial intelligence, human–machine interfaces, health monitoring, and soft robotics. To obtain piezoresistive pressure sensors with improved sensitivity and reliability in sensing performance, we investigated the correlation between the pressure-sensing performance of the sensors and the nanostructures of the sensing media with controlled nanopatterned templates. To compare the effects of nanostructures on the pressure sensor performances, two nanorod-patterned sensing media with different nanoscales were used: one was a finely nanopatterned sensing medium, while the other was a relatively large nanopatterned medium using different anodized aluminum oxide (AAO) templates, named shAAO and bhAAO, respectively. The piezoresistive pressure sensor using the shAAO-replicated sensing medium exhibited better sensitivity, faster response/recovery rate, and better sensing reliability than the bhAAO-pressure sensor. This result suggests that optimizing the nanopatterned structures should be considered in terms of the interdigitated contact that proceeds between the two electrodes to obtain high-performance pressure sensors when designing nanopatterned sensing media applied through face-to-face assembly of the nanostructured substrate.