Flexible\nand Transparent Pressure/Temperature Sensors\nBased on Ionogels with Bioinspired Interlocked Microstructures

Abstract

Bioinspired\nby the interlocked geometry between the epidermal–dermal\nlayers of natural skin, here we design a flexible and transparent\n(94.2%) skin-like sensor with an interlocked hexagonal microcolumn\narray structure based on ionogels of ionic liquids (ILs) and thermoplastic\npolyurethane (TPU) assisted by laser-etched silicon wafers. Attributed\nto the bioinspired microstructure, the resulting interlocked TPU@IL\nionogel sensor exhibits outstanding pressure-sensing properties, which\nhas an ultralow detection limit (∼10 Pa) and ultrafast responsiveness\n(∼24 ms). Interestingly, it is worth noting that the interlocked\nTPU@IL ionogel sensor also has high temperature-sensing performance\nbecause of the dependence of the ionic conductivity of ILs on the\ntemperature, which can accurately detect a slight temperature change\n(0.1 °C). Moreover, the interlocked TPU@IL ionogel sensor can\nalso serve as the strain sensor in the strain range of 0.1–10%.\nAttributed to the intrinsically antibacterial effect of ILs, the interlocked\nTPU@IL ionogel sensor possesses an antibacterial function, which is\na desired merit of wearable electronics and devices. The current study\nprovides a novel strategy to manufacture transparent, flexible, and\nantimicrobial e-skin sensors with multiple sensing capabilities, which\nmay inspire more future research studies for e-skins.