Bioinspired, multifunctional dual-mode pressure sensors as electronic skin for decoding complex loading processes and human motions

Mimicry of the somatosensory system in the human skin via electronic devices exhibits broad applications in intelligent robotics and wearable electronics. Here, we report a novel biomimetic flexible dual-mode pressure sensor that is based on the interlocked piezoelectric and piezoresistive films with pyramid microstructures. The sensitivity of the sensor is significantly enhanced because of the induced larger stain variation along the thickness direction of the former piezoelectric film and increased contact area in the latter piezoresistive film. The synergistic effect of the piezoelectric and piezoresistive responses to stimuli also allows the dual-mode sensor to detect over broad pressure and frequency ranges. The analysis of these signals can deconvolute multiple aspects of the complex stimuli loading processes, including their loading direction, rate, magnitude, and duration. As a proof-of-concept demonstration, the dual-mode pressure sensor is successfully integrated with manipulators and human bodies to decode the complex and delicate picking processes and human motions, respectively. When combined with the other sensing modalities, the multifunctional dual-mode pressure sensor delivers new application opportunities in intelligent soft robotics and human-machine interfaces.