High-Density Ionic Skin via Direct Microlithography of Photosensitive Ionogel

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/cm 2 . 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.