The Venus Flytrap Inspired Strategy for High-Sensitivity Omnidirectional Tactile Hair

Abstract Tactile sensors are essential for human–machine interfaces, robotics, and health monitoring; however, they suffer from critical limitations, including stress dissipation, restricted omnidirectional sensitivity, and fatigue failure. Inspired by the stress localization mechanism of Venus flytrap trigger hairs, this study presents a biomimetic piezoresistive sensor exhibiting high sensitivity, 360° lateral perception, and multidirectional sensing potential. The device employs a heterogeneous cantilever structure, comprising a rigid resin microcone and a flexible PDMS substrate, to amplify and lock contact forces. Furthermore, a composite piezoresistive material incorporating liquid metal microdroplets as dynamic conductive bridges is embedded in the high-strain region. This design effectively overcomes the inherent trade-off between achieving an ultralow detection limit and maintaining 360° lateral perception with multidirectional sensing potential. The results demonstrate that the device accurately captures extremely weak stimuli, including those induced by water droplets, gentle breezes, and insect locomotion. Moreover, the device has been successfully applied to 0.3-mm-resolution surface roughness mapping and fast-response humidity sensing, offering a versatile paradigm for high-fidelity, 360° lateral detection with multidirectional sensing potential of weak mechanical signals.