High‐Density Ionic Skin via Direct Microlithography of Photosensitive Ionogel

Abstract Ionic skin with ionic mechanotransduction similar to human skin can perceive stimuli by ionic conduction, holding great potential in novel human‐machine interactions. However, the high‐density integration of ionic skins still faces significant challenges due to the difficulty in fabricating high‐density patterned ionogel arrays with simple manufacturing processes. Herein, the study reports a high‐density ionic skin (HI‐Skin) based on ionogel array patterned by direct microlithography. The photosensitive ionogel (PIG) is synthesized by rapid ultraviolet‐induced in situ photopolymerization process. The direct microlithography of PIG is developed, which allows to directly pattern ionogel precursors by selective exposure to ultraviolet light and development. Simple and low‐cost preparation of PIG array with the minimum line width of 200 µm is realized. Furthermore, HI‐Skin is constructed by integrating patterned PIG arrays with row and column electrodes, and the density is up to 49/cm². The HI‐Skin demonstrates high sensitivity of 126.8 kPa⁻¹ and low crosstalk of −8.93 dB. By integrating the HI‐Skin and a microcontroller, a multichannel signal acquisition system is built to achieve detection of multiple motion trajectories. This work opens an avenue for the simple construction of high‐density ionic skin.