The influence of adhesion on crumpled films

Understanding the mechanics of random networks is currently one of the most important problems facing the soft-matter community due, in part, to the broad role random networks play in Nature. Recently, researchers have focused on the crumpling of a thin sheet as a useful model random network with unique features due to the increased non-crossing constraints faced by a sheet (compared to a chain). While several models have been proposed, all have ignored the role of inter-sheet adhesion in the process. In this work, we will show how adhesion modifies several features of the crumpling process. We perform compression experiments with several polymeric materials in which adhesion can be controlled, examining the static and dynamic features of the crumpled state. Most notable of our results is that fitting force-displacement data to a simple empirical power law reveals an order of magnitude increase in the effective Young’s modulus of the crumpled network.