Low-crosstalk iontronic e-skin for high-fidelity tactile perception

High-density tactile sensor arrays are essential for applications such as Braille reading but remain limited by the intrinsic trade-off between sensitivity and mechanical crosstalk. Here we introduce a capacitive array with a gradient high/low modulus strain isolation layer (G-HL-SIL) that suppresses non-local strain transfer while preserving high normal compressibility. Finite element analysis together with experiments reveals how structural parameters govern strain propagation and establishes design principles for balancing sensitivity and crosstalk in dense arrays. Guided by these principles, the array achieves a sensitivity of 3.92 kPa^-1 with a crosstalk coefficient reduced to 4.39%. Integrated into a slide-recognition-vocalization platform, the system enables 100% static Braille recognition accuracy and 99 % dynamic recognition accuracy, while simultaneously lowering mis-triggering events during data acquisition by over 70%. This dual enhancement in accuracy and robustness demonstrates a generalizable strategy for high-density electronic skins and offers a practical pathway toward assistive technologies for the visually impaired.