Wet-responsive and reconfigurable hydrogel fastener with enhanced wet adhesion in biomedical applications

Abstract

Recently, the demand for specialized adhesives under wet conditions as well as dry adhesives is steadily increasing, particularly in the biomedical field. Especially, the adhesive 3,4-dihydroxy-L-phenylalanine (DOPA) inspired by mussels has been a representative example for various artificial under wet adhesives. Nevertheless, most DOPA-based adhesives need reversible curing agents due to irreversibly crosslink the residues to the surface. Herein, we investigated a high stable and fixation-like interlocked adhesive as a reversible interlocking system based on the simple mushroom-shaped arrays of low aspect ratio (AR ~0.65). To examine the mechanical behavior of interlocking system, several different geometries were applied by changing the pitches (25,30, 35, and 40 um) of patterns having a width of 20 um. The interlocking system is carried out a physical interlocking that tightly joins the two surfaces without any chemical treatment. It was observed that the shear forces under wet condition were maximized with pitch 25 um due to the swelling effect of PEGDMA. In accordance with the development of interlocking system under wet condition, this study can pave the way for the realization of robust and smart interlocking system for a diverse range of applications, including those involving wet assembly of components.