Determination of thin-film debonding parameters from telephone-cord measurements

Methods are put forward for the determination of the fracture energy and kinetic coefficient of thin film/substrate interfaces from measurements performed on telephone cord blisters. This work is based on a previously proposed model for the characterization of debonding features in compressed thin films. The advantages of the proposed methods stem from the following facts concerning telephone cord blisters: (i) they are spontaneous debonding features, and therefore more amenable than artificially contrived features to yield realistic debonding parameters; (ii) they are very commonly observed in compressed thin films; (iii) as revealed by our model, their boundaries are characterized by a constant fracture mode mixity, and (iv) the driving force for debonding equals the fracture energy everywhere on their boundaries.