Pressure Induced Molecular-Arrangement and Charge-Density Perturbance in Doped Polymer for Intelligent Motion and Vocal Recognitions

Abstract

Conjugated polymers (CPs) show great potential for pressure detection due to the amorphous polymer packing, but a lack of clarity regarding sensing mechanisms hampers the development of further applications. Herein, a sacrificial template-full solution method with both rough surface and high conductivity is described that can be applied to sandwich-structured resistive pressure sensors. Transient absorption measurements demonstrate the significant increase of carrier lifetime (from 1.44 to 2.54 ns) induced by pressure, which directly evidenced the superior sensing mechanism of sidechain doped conjugated polymer. This sensor displayed low-pressure detection limit of 0.7 Pa as well as a rapid response time of 18.8 ms, enabling multi-mode motion analysis including wrist pulse, swallowing, finger bending, grabbing, and typing. Additionally, an intelligent vocal recognition system with convolutional neural networks is used which can achieve >96% classification accuracy across diverse vocal profiles. This general approach is anticipated and enables a new direction for the development of pressure sensors.