Folding, wrinkling, and creasing of polymer multilayer films

Ryan Hayward
University of Massachusetts Amherst
Thursday, September 25, 2014
NCSU Centennial Campus | Monteith Research Center #313 @ 4:30pm

Soft polymer networks, such as gels and elastomers, can undergo a wide variety of geometry-dependent mechanical shape instabilities when subjected to compressive stresses, providing opportunities to tailor the structure and properties of stimuli-responsive materials. These include global buckling modes of unsupported sheets as well as local surface modes such as wrinkling and creasing. The introduction of two or more elastic layers provides a multi-dimensional parameter space in terms of contrasts in stiffness, geometry, and pre-strain between the layers, yielding a rich landscape of behaviors. In one example, we have recently studied the buckling of unsupported elastic trilayers as a route to define self-folding and responsive three-dimensional objects based on origami design principles. In another, we have considered the role of mismatch strain in surface instabilities such as creasing and wrinkling, which allows for fine control over both the types of surface modes that appear and their hysteretic behavior.