Adhesion between highly stretchable materials.

Recently developed high-speed ionic devices require adherent laminates of stretchable and dissimilar materials, such as gels and elastomers. Adhesion between stretchable and dissimilar materials also plays important roles in medicine, stretchable electronics, and soft robots. Here we develop a method to characterize adhesion between materials capable of large, elastic deformation. We apply the method to measure the debond energy of elastomer-hydrogel bilayers. The debond energy between an acrylic elastomer and a polyacrylamide hydrogel is found to be about 0.5 J m(-2), independent of the thickness and the crosslink density of the hydrogel. This low debond energy, however, allows the bilayer to be adherent and highly stretchable, provided that the hydrogel is thin and compliant. Furthermore, we demonstrate that nanoparticles applied at the interface can improve adhesion between the elastomer and the hydrogel.