Tissue adhesion with tough hydrogels: Experiments and modeling

Tissue adhesion has profound implications in numerous applications ranging from wound management to wearable devices. Recent advances witness the creation of tough hydrogel-based adhesives capable of forming tough tissue adhesion. While attention has been paid on the interfacial chemistry and the adhesive matrix, the role of tissue mechanics on tough hydrogel-tissue adhesion remains largely unexplored. Increasing evidence shows that the adhesion varies with tissues. Here, we investigate the tissue adhesion with tough hydrogels experimentally and computationally. A finite element model is developed to simulate rate-independent adhesion between tough hydrogels and various tissues, including skin, liver and blood vessels. The parameters used in the model are measured experimentally or extracted from the literature. The computational model agrees well with the experimental data, and further reveals the quantitative dependence of tough hydrogel adhesion on the elastic modulus and dissipative properties (i.e., Mullins effect) of tissues. The underlying mechanisms for these findings are discussed. This study provides a holistic modelling of tough hydrogel-tissue adhesion and sheds light on the development of tissue-specific adhesives for precision and personalized medicine.