Intrinsically polar elastic metamaterials
Abstract
The ability to design and fabricate materials with tailored mechanical properties, combined with immunity to damage, is a frontier of materials engineering. For example, materials which are characterized by elastic properties that depend on the position inside a medium are required in applications where structural stability has to be combined with a soft and compliant surface, like in impact protection and cushioning. A gradient in the elastic properties can be built from a single material, varying gradually the bulk porosity of the material or its geometrical structure. However, if such a gradient is built into the material at production, damage or wearing over time might expose unwanted elastic properties. Here, we implement a design principle for a spatially inhomogeneous material based on topological band-theory for mechanical systems. The resulting inhomogeneity is stable against wearing and even cutting the material in half. We show how, by creating a periodic elastic material with topological properties, one can create an intrinsically polar behavior, where a face with a given surface normal is stiff while its opposing face is soft.
Cite
@article{arxiv.1707.01504,
title = {Intrinsically polar elastic metamaterials},
author = {Osama R. Bilal and Roman Süsstrunk and Chiara Daraio and Sebastian D. Huber},
journal= {arXiv preprint arXiv:1707.01504},
year = {2017}
}