Mechanical Phase Transformation Along Multiple Transition Pathways

Mechanical metamaterials comprising coupled, multi-stable structural units are recognized for their reconfigurability, which has proposed applications in mechanical computing, soft robots, and shape morphing among others. Most prototypes utilized a bi-stable unit cell for which the transition between stable states occurs along a single minimum energy pathway. In this talk, we will introduce a class of metamaterial whose bi-stable unit cells may effectuate a state transition along any of multiple low-energy pathways, yield usualy results: transition waves that form stable structures rather than annihilate following collision and exhibit path-dependent kinetics, as well as heterogeneous, self-pinning domain walls. One consequence is the ability to realize stable complex 2D phase morphologies without the aid of structural defects which would diminish the degree of reconfigurability. As an example, we demonstrate a waveguide for transition waves, which may be spontaneously (re)created and reimagined.