Synergistic Structural Construction of Strain Sensors with Low Baseline Drift and High Sensitivity for Continuous Dynamic Monitoring.

Abstract

Strain sensors based on conductive elastomers face challenges like baseline drift and noise due to inherent viscoelasticity and weak electrode interfaces under dynamic strains. Herein, a synergistic structure with biphasic hierarchical networks and stable electrode interfaces is proposed to address these issues. The sensor employs a multilayer structure with polydimethylsiloxane (PDMS) substrate, carbon nanotube-doped PDMS (CNT-PDMS), and Ag film. Electrodes are fixed using a rigid island reinforced mortise and tenon joint formed with PDMS and CNT-PDMS. The Ag film dominates resistance during release, significantly reducing baseline drift. Strain-insensitive electrode interfaces further reduce baseline drift and noise. This optimized design ensures 99.999% resistance recovery without delay, even at high-speed (800 mm/min) and large (80%) strains. The sensor exhibits a high gauge factor of 55442, low detection limit (0.02%), and excellent stability (5000 cycles). With the designed algorithms, the single-channel sensor achieves 98.2% decoding accuracy for various gestures, demonstrating great potential for wearable electronics.