Lithium Bond-Mediated Molecular Cascade Hydrogel for Injury-Free and Repositionable Adhesive Bioelectronic Interfaces

Flexible bioelectronic interfaces with adhesive properties are essential for advancing modern medicine and human-machine interactions. However, achieving both stable adhesion and non-damaging detachment remains a significant challenge. In this study, a lithium bond-mediated molecular cascade hydrogel (LMCH) for bioelectronic interfaces is designed, which facilitates robust adhesion at the tissue level and permits atraumatic detachment for repositioning as required. By integrating the adhesive properties of the molecular cascade structure with the elastic characteristics of the hydrogel interface, the LMCH interface not only achieved a high adhesion strength (197 J m^-2) on the skin, but also significantly extended the cracking cycles on the tissue surface during the peeling process from 4 to 380, marking an enhancement of nearly two orders of magnitude. Furthermore, with Young's modulus similar to that of human tissue (25 kPa), exceptional stretchability (1080%), and high ionic conductivity (7.14 S m^-1), the LMCH interface demonstrates outstanding tissue compatibility, biocompatibility, and stable detection capabilities for electrocardiogram (ECG) and electromyogram (EMG) signals. This study presents new insights and potential for advancing bioelectronics and implantable interface technologies.