Highly stretchable, compressible, adhesive hydrogels with double network

In this work, a double network bovine serum albumin-polyacrylamide (BSA-PAM) adhesive hydrogel was fabricated, in which combination of physical interactions including hydrogen bonds and chain entanglements, and chemical covalent photo-crosslinking. The BSA-PAM hydrogel exhibited excellent mechanical and adhesive properties. The composite hydrogel not only demonstrated excellent tensile properties (maximum force elongation 1552%~2037%), but also displayed extremely high fatigue resistance even when subjected to compress strains of up to 85%. More importantly, the BSA-PAM hydrogel showed excellent adhesiveness to various substrates (90 kPa~150 kPa for glass and 9.74 kPa~35.09 kPa for pigskin). This work provided a facile way of fabricating tough, stretchable and adhesive BSA-PAM hydrogels.