摘要
Electronic skin (e-skin) holds significant potential for applications in health monitoring, human–machine interface, and motion recognition. However, conventional e-skins often exhibit decreased sensitivity and delayed response in low-temperature environments due to the freezing of conductive materials. To solve this, a flexible e-skin suitable for low-temperature environments was fabricated by selecting the ionic liquid [BMIM]BF4 as the conductive medium. Unlike liquid metals and hydrogels, ionic liquids can serve as conductive media with ultralow melting points and high conductivity by selecting appropriate cation–anion combinations. The [BMIM]BF4 we selected maintains high conductivity even with an ultralow melting point of −71 °C, which enables the fabricated flexible sensors to exhibit outstanding pressure-sensing performance under low-temperature environments. The e-skin can accurately respond to pressure loads (100–10,000 Pa), with linear resistance response. In addition, the e-skin maintains stable sensing performance in various curved environments and retains its normal sensing capability for external loads at temperatures as low as −50 °C. Furthermore, it possesses excellent dynamic sliding trajectory recognition capabilities, enabling the simultaneous identification of trajectories from multipoint sliding. To further enhance the three-dimensional microscale sensing capabilities of the e-skin, micropyramids were introduced onto its surface. The micropyramid-decorated e-skin can accurately achieve real-time dynamic detection of height at −10 °C, with a detection error of less than 2%. Therefore, the e-skin can accurately recognize microscale three-dimensional surface morphologies at −10 °C. Moreover, this e-skin can be applied in the field of Braille detection. It exhibits good recognition and reading capabilities for standard Braille currently in use and can identify various complex Braille letters.
危险品化学品经营许可证（带存储）