Three-dimensional Printed Ultrahighly Sensitive Bioinspired Ionic Skin Based on Submicrometer-Scale Structures by Polymerization Shrinkage

Ionic skin with a high performance has been extensively explored due to its ability to convert external stimuli into obvious electrical signals for wearable electronics and intelligent detection. However, due to the unmatched Young's moduli between the elastic substrate and the conductive layer, rapidly manufacturing durable ionic skin with ultrasensitivity over a wide range of pressures is still a great challenge. Here, we report a new strategy of 3D printing polymerizable deep eutectic solvent (PDES) for the manufacture of highly sensitive bioinspired ionic skin over a wide range of pressures via photopolymerization shrinkage formed submicrometer-scale protrusions on bioinspired skin structures. The 3D patterned poly(PDES) ionic skin (interlocked pyramid type with submicrometer protrusions) can realize "all-in-one" ability with high transparency, compressibility, and intrinsic conductivity, displaying ultrabroad range pressures (0.6 Pa-2 MPa) with superhigh sensitivity (348.28 KPa-1) and high electrical durability (at 0.35 MPa for 45 000 cycles). Furthermore, these excellent abilities allow as-prepared ionic skins to serve as visually detected pressure sensors for precision instruments, providing great potential in flexible wearable monitoring equipment and human-computer interaction.