Yair Shokef（Tel Aviv University) Knots, Physics and the Reconnection of Vortices

Abstract

We study two- and three-dimensional mechanical metamaterials with anisotropic unit cells. When the orientation of each one is set at random they typically form a frustrated structure. We present a combinatorial strategy for the design of a multitude of non-periodic, yet frustration-free metamaterials that exhibit spatially textured functionalities. We demonstrate these by designing three-dimensional metacubes, which when compressed can deform to give any pre-defined texture on their faces. In two dimensions, we introduce topological defects possessing global frustration that cannot be removed by local structural changes. We uncover the distinct mechanical signature of topological defects by experiments and simulations, and leverage this to design complex metamaterials in which we can steer deformations and stresses towards parts of the system.