Effects of bending stiffness and roughness on the peeling behavior of an elastic thin film on a rigid substrate

The peeling behaviors of an elastic thin film perfectly adhering on a smooth and a corrugated substrate are investigated theoretically with the method of the minimum potential energy. The whole peeling process, from the initiation of debonding to the steady-state stage, is characterized. Typical peeling force-displacement relations as well as the deformed profiles of the film are obtained analytically at different peeling angles and bending stiffness. For the case of a thin film adhering on a corrugated substrate, the surface roughness can significantly improve the peeling strength. Spontaneous detachment happens locally at the valley or crest of each asperity when the roughness is large enough. The results derived in this paper should be very helpful in the design and assessment of the film/substrate interface.