Bioinspired Poisson‑actuated gating enabled high-sensitivity and stretchable multidirectional strain sensing

Abstract Decoupling strain magnitude and arbitrary orientation is a persistent challenge for wearable strain sensors, as conventional layered architectures and monolithic anisotropic networks suffer from issues of interfacial stress concentrations and irreversible signal drift under complex deformations. Inspired by the mechanogating mechanism of tactile sensory cells, we present a fluidic strain sensor with an orthogonal cross-shaped microchannel network and drum-shaped microstructures. The unique drum-shaped geometry exploits the Poisson effect to amplify transverse gap closure, inducing channel constriction. This mechanism yields a peak gauge factor exceeding 43,200 near gap closure—a four-order-of-magnitude enhancement over unstructured fluidic channels. The orthogonal architecture achieves intrinsic directional selectivity—the longitudinal channel elongates and narrows while the transverse channel shortens and widens—delivering a near-axial average directional selectivity of 15.42. By leveraging machine learning, the sensor achieves quadrant-resolved strain sensing with sub-2° angular resolution over 80% strain range, provided the loading quadrant is known. The fluidic transduction mechanism circumvents the mechanical fatigue inherent to solid-state sensing materials, demonstrating exceptional durability over 100,000 cycles. The practical utility is validated through table tennis stroke recognition achieving >95% accuracy, highlighting its potential for closed-loop athletic training and resilient human-machine interfaces.