Ultrahigh-Linear Bio-Inspired Janus Elastomeric Strain Sensor with High Sensitivity and Stretchability via Surface Wrinkle Engineering.

Abstract

In pursuit of high-performance flexible strain sensors, achieving an optimal trade-off among linearity, sensitivity, and strain sensing range remains a critical challenge. Inspired by the wrinkled-leaf viburnum, we develop a Janus sensor that replicates its asymmetric structure. It comprises a dense, micro-wrinkled natural rubber (NR)/graphene (GRs) top layer and a loose NR/carbon nanotubes (CNTs) bottom layer, fabricated via facile layer-by-layer filtration and pre-stretching strategy. This bio-inspired design enables the sensor with a synergistic sensing mechanism: wrinkle-guided microcrack ensures highly sensitive linear response at low strains; strain-phase division maintains signal continuity at medium strains; and parallel conductive circuits provide robustness at high strains. As a result, the sensor achieves an exceptional combination of ultra-high linearity (R² > 0.999) and sensitivity (gauge factors, GF > 14) across 0-100% strain, with a wide sensing range (> 400%) and fast response (0.16 s). We demonstrate its practical value in human motion detection, physiological signal monitoring, and an intelligent glove system for gesture recognition and human-machine interaction, highlighting its promising potential for advanced wearable devices and human-machine interactive systems.