Thursday, November 7, 2013
Mechanical and Civil Engineering Seminar
Pattern Formation in Soft Elastic Films and Methods to Enhance Adhesion
Manoj Chaudhury, Professor, Department of Chemical Engineering, Lehigh University
The main story is about the elastic instability, and its role in the adhesive crack propagations in different configurations involving soft confined films. We will discuss two regimes: one in which the surface tension forces related to the deformation of its free surface is negligible, and the other in which it is significant. The latter case is of considerable importance in thin film adhesives, where the failure stress digresses somewhat from the familiar expressions of fracture mechanics. The capillarity, elasticity and even gravity can also give rise to several intercepting length scales in such ultra-soft elastic systems that can be used to explore novel phenomena, one being the self-organization of particles in a soft elastic matrix. If time permits, we will present a related story about some simple artificial patterns that can be used to control the adhesion of thin elastomeric films. We will provide examples of how cracks can be arrested in such patterned films, thereby enhancing the adhesive strengths of low energy films in contact with various substrates.