Hierarchical hybrid crosslinking multifunctional gelatin-based hydrogel: ideal platforms for flexible wearable devices, brain–computer interfaces and biomedical applications

Hydrogels are promising candidates for flexible wearable technology, biomedicine, and even brain–computer interfaces (BCI). However, the mismatch in the mechanical properties and high biotoxicity of the materials cast a shadow on their application prospects. Herein, we developed a multifunctional hydrogel matrix primarily based on the natural polymer gelatin. Multilevel hybrid dynamic crosslinking (MHC) enables the adjustment of the hydrogel molecular network and endows the material with satisfactory mechanical properties and self-healing behavior. The excellent biocompatibility of the hydrogel is enough to support the growth and proliferation of cells while avoiding tissue rejection or inflammation. Moreover, the excellent self-adhesive performance allows the hydrogel to directly adhere to the surface of human skin and tissues, enabling real-time monitoring of body movements and non-invasive sensing of electroencephalogram (EEG) signals. Therefore, the multifunctional hydrogel matrix with self-adhesive behavior, self-healing properties, appropriate mechanical performance, and excellent biocompatibility can be regarded as a promising platform for applications in flexible wearable devices, biomedical materials, and BCI devices.