A Biomimetic Fiber-Entangled Permeable Electronic Skin for Strain-Insensitive and High-Resolution Tactile Sensing

Electronic skins (e-skins) incorporating island architectures represent a promising platform for strain-insensitive tactile sensing by mechanically decoupling sensing units from deformations. However, conventional island designs encounter stress concentration issues caused by inherent modulus mismatches, critically limiting achievable island densities. This limitation forces a stubborn trade-off between strain-insensitivity and sensing resolution. Here, inspired by the entangled elastin networks surrounding human tactile receptors, a biomimetic fiber-entangled island architecture is proposed that addresses the stress concentration issue, providing a viable solution for strain-insensitive and high-resolution tactile sensing. The mechanism by which the fiber-entangled architecture mitigates stress concentration is based on the strain-dependent reorientation of its constituent fibers. As a demonstration of this solution, a pressure sensing e-skin exhibiting simultaneous high resolution (100 unit cm^-2) and low strain interference (gauge factor < 0.03) is developed. Implemented with artificial neural networks, the e-skin demonstrates proof-of-concept functionality as a wearable Braille point-to-read system. The fiber-entangled architecture proposed here will emerge as a versatile platform for next-generation humanoid sensing.