Adv Mater. 2022 Feb;34(5):e2105338. doi: 10.1002/adma.202105338. Epub 2021 Dec 10.

Electrostatic-Mechanical Synergistic In Situ Multiscale Tissue Adhesion for Sustainable Residue-Free Bioelectronics Interfaces

Da Wan Kim, Kang-Il Song, Duhwan Seong, Yeon Soo Lee, Sangyul Baik, Jin Ho Song, Heon Joon Lee, Donghee Son, and Changhyun Pang

Abstract

Recent studies on soft adhesives have sought to deeply understand how their chemical or mechanical structures interact strongly with living tissues. The aim is to optimally address the unmet needs of patients with acute or chronic diseases. Synergistic adhesion involving both electrostatic (hydrogen bonds) and mechanical interactions (capillarity-assisted suction stress) seems to be effective in overcoming the challenges associated with long-term unstable coupling to tissues. Here, an electrostatically and mechanically synergistic mechanism of residue-free, sustainable, in situ tissue adhesion by implementing hybrid multiscale architectonics. To deduce the mechanism, a thermodynamic model based on a tailored multiscale combinatory adhesive is proposed. The model supports the experimental results that the thermodynamically controlled swelling of the nanoporous hydrogel embedded in the hierarchical elastomeric structure enhances biofluid-insensitive, sustainable, in situ adhesion to diverse soft, slippery, and wet organ surfaces, as well as clean detachment in the peeling direction. Based on the robust tissue adhesion capability, universal reliable measurements of electrophysiological signals generated by various tissues, ranging from rodent sciatic nerve, the muscle, brain, and human skin, are successfully demonstrated.