Soft strain-insensitive bioelectronics featuring brittle materials

• Published in: Science (American Association for the Advancement of Science) Vol. 378; no. 6625; pp. 1222 - 1227
• Main Authors: Zhao, Yichao, Wang, Bo, Tan, Jiawei, Yin, Hexing, Huang, Ruyi, Zhu, Jialun, Lin, Shuyu, Zhou, Yan, Jelinek, David, Sun, Zhengyang, Youssef, Kareem, Voisin, Laurent, Horrillo, Abraham, Zhang, Kaiji, Wu, Benjamin M, Coller, Hilary A, Lu, Daniel C, Pei, Qibing, Emaminejad, Sam
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 16-12-2022
• Subjects: Animals; Biocompatible Materials; Biomaterials; Biomedical materials; Brittle materials; Brittleness; Carrier mobility; Charge transport; Cracks; Current carriers; Elastomers; Electric Conductivity; Electronics; Human tissues; Implantable Neurostimulators; Mice; Strain energy
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.abn5142

Advancing electronics to interact with tissue necessitates meeting material constraints in electrochemical, electrical, and mechanical domains simultaneously. Clinical bioelectrodes with established electrochemical functionalities are rigid and mechanically mismatched with tissue. Whereas conductive materials with tissue-like softness and stretchability are demonstrated, when applied to electrochemically probe tissue, their performance is distorted by strain and corrosion. We devise a layered architectural composite design that couples strain-induced cracked films with a strain-isolated out-of-plane conductive pathway and in-plane nanowire networks to eliminate strain effects on device electrochemical performance. Accordingly, we developed a library of stretchable, highly conductive, and strain-insensitive bioelectrodes featuring clinically established brittle interfacial materials (iridium-oxide, gold, platinum, and carbon). We paired these bioelectrodes with different electrochemical probing methods (amperometry, voltammetry, and potentiometry) and demonstrated strain-insensitive sensing of multiple biomarkers and in vivo neuromodulation.