The role of interfacial friction on the peeling of thin viscoelastic tapes

We study the peeling process of a thin viscoelastic tape from a rigid substrate. Two different boundary conditions are considered at the interface between the tape and the substrate: stuck adhesion, and relative sliding in the presence of frictional shear stress. In the case of perfectly sticking interfaces, we found that the viscoelastic peeling behavior resembles the classical Kendall behavior of elastic tapes, with the elastic modulus given by the tape high-frequency viscoelastic modulus. Including the effect of frictional sliding, which occurs at the interface adjacent to the peeling front, makes the peeling behavior strongly dependent on the peeling velocity. Also, at sufficiently small peeling angles, we predict a tougher peeling behavior than the classical stuck cases. This phenomenon is in agreement with recent experimental evidences indicating that several biological systems (e.g. geckos, spiders) exploit low-angle peeling to control attachment force and locomotion.