Ultra-sensitive, durable and stretchable ionic skins with biomimetic micronanostructures for multi-signal detection, high-precision motion monitoring, and underwater sensing

Abstract

Skin-like ionogels have attracted much attention in artificial electronic skins and wearable sensors. However, it is challenging to develop ionogel-based multifunctional sensors that exhibit favorable durability, high sensitivity, and multisignal detection capability in diverse application environments. Herein, a mechanically durable, highly stretchable, and ultra-sensitive micronanostructured ionogel-based i-skin (MIS) with biomimetic hierarchical structures is fabricated. Moreover, with the highly conductive MIS as an ionic conductive layer, a MIS-based sensor with excellent superhydrophobicity has been developed by sandwiching the MIS film between two layers of acrylic elastomer film. By virtue of the well-designed surface structure and ingenious combination of various fascinating functions, the resultant MIS sensor features prominent sensing performance, including a wide sensing range of strain (0.1–400%), pressure (0.001–15 kPa), and temperature (25–95 °C), an ultralow detection limit (0.1% strain and 0.001 kPa pressure), a rapid response (67 ms), and ultra-durable stability (over 10 000 uninterrupted strain or compression cycles), showing competitive and even superior comprehensive performance to those of the existing ionogel sensors. Significantly, the versatile MIS sensor can not only be applied in wearable movement monitoring, multi-signal detection, and high-precision written stroke recognition, but is also capable of detecting subtle underwater vibrations caused by liquid drops or waves, a robotic fish, or human action, demonstrating its greater potential for diverse applications such as human health monitoring, human–machine interaction, marine environmental protection and biological research.