Intrinsic‐Decoupled Biomimetic Two‐Dimensional Sensing Enabled by Positive‐Negative Dielectric Heterostructures for Pressure Visualization

ABSTRACT

Flexible tactile sensors capable of simultaneously emulating the multidirectional perception of human skin and realizing intrinsic force decoupling remain a critical challenge for advanced robotics and intelligent human‐machine interfaces. Inspired by the hierarchical architecture of epidermal cells, we present a two‐dimensional force sensor (TDFS) featuring a biomimetic heterostructure that enables structural separation of normal and tangential force components. Force discrimination is enabled by engineering a negative‐permittivity composite with a gradient‐modulus architecture that mechanically reduces the overlap between deformation fields induced by normal and tangential loading. Additionally, benefiting from this structural design and a differential capacitive scheme, the TDFS exhibits reduced inter‐axis coupling within the calibrated loading range and a high angular resolution of 1.5° ranging from 20 to 30 N. The TDFS device provides monotonic normal and tangential responses over 0–30 N, exhibiting high detection sensitivity. Through optimization of the parameters, a separate normal device fabricated with Ni _0.9 achieves a peak normal sensitivity of −892.933 N ^{− 1} within the 27–30 N loading range. A customized readout circuit was further developed to enable stable signal acquisition from the negative‐capacitance sensing system. The synergistic design facilitates directional force perception and provides a reliable and scalable solution for next‐generation multidimensional electronic skins.