Kinks and breathers in mechanical metamaterials

Flexible elastic metamaterials (flexEM) are architected structures known for their ability to support large elastic deformations, with key features, such as buckling under critical loads, bistability, and zero modes. By leveraging concepts from condensed matter physics—such as symmetry breaking, topological band theory, and frustration—flexEMs enable the observation of rich nonlinear phenomena previously studied in other settings, including conducting polymers, atomic wires, and ferroelectric phase transitions. This talk, building on recent progress in understanding the static behavior of bistable flexEMs, will explore their dynamic response. Using simplified mass-spring lattice models, which effectively capture their elastodynamic behavior, I will focus on nonlinear waves, such as kink solutions and breathers, their collisions, and interactions with linear phonon wavepackets. By investigating these nonlinear dynamics, we aim to propose strategies for dynamically controlling the structure of flexEMs—such as manipulating kink motion to overcome the Peierls barrier or triggering transition waves through breather collisions. The ultimate goal is to deepen our understanding of flexEM dynamics and provide insight into the design of reconfigurable metamaterials for applications in advanced mechanical devices, soft robotics.