Abstract: Peeling is a ubiquitous process, which is important to many applications in engineering and biology. The peeling of homogeneous elastic tape from a rigid substrate has been studied widely.  While there is a good understanding of the homogenized behavior of heterogeneous materials concerning properties such as the overall elastic moduli that are characterized by a variational principle, much remains unknown concerning those properties that are characterized by evolutionary processes such as fracture.  This talk will discuss the process of peeling a heterogeneous adhesive tape from a rigid substrate as a case study to demonstrate the complexities that can arise in this situation.  Specifically, it is shown through experimentation and theoretical analysis that one can dramatically enhance the overall adhesive strength by patterning the elastic modulus of the tape.  It is also shown that by patterning the adhesive, asymmetry can be induced where the force needed to peel the membrane depends not only on the direction but also the sense of the peel.  Remarkably, these modifications in peeling strength come from variations in the energy associated with bending of the tape near the peeling front which is negligible compared to the overall energy in the system. This illustrates that in evolutionary processes, perturbations with apparently negligible energy can have an anomalously large macroscopic effect. The talk will conclude with broader lessons for other phenomena including fracture, dislocations, phase boundaries and wetting fronts.