Reversible Electrochemically Triggered Delamination Blistering of Hydrogel Films on Micropatterned Electrodes

adhesion, [ 14,15 ] wetting, [ 16,17 ] and optical characteristics [ 18 ] of surfaces, among other examples. In comparison to other buckling modes, delamination—wherein a supported elastic thin fi lm subject to a compressive mismatch strain undergoes debonding from the substrate and forms blister-like structures—has received relatively little attention with regards to applications in responsive materials or soft actuators. Although well-known from the perspective of failure of a diversity of thin coatings including paint, metals and inorganic materials, [ 19,20 ] graphene [ 21–25 ] and polymer fi lms, [ 26–32 ] and of recent interest in the growth of biofi lms, [ 33–35 ] only a few studies have sought to exercise control over this process to defi ne switchable materials. Notably, Huck and co-workers demonstrated the triggered electrochemical delamination of cross-linked polymer brush fi lms from patterned electrodes, although in this case the process was irreversible. [ 36 ] Very recently, Rogers and co-workers have relied on delamination buckling of metal fi lms with patterned adhesion to generate reversibly tunable 3D structures, [ 37 ] while Zhao and co-workers have used delamination of graphene fi lms to tune surface wetting and transparency. [ 38 ]