Mechanical Metamaterials

MURI Project funded by ONR: Active and Reconfigurable Topological Mechanical Metamaterials from the Nanoscale to the Macroscale New forms of warfighting capabilities such as warfighter enhancement, advanced sensing & response, environmental surveillance require next-generation materials with active and triggerable properties in the battlefield environment. Mechanical metamaterials (MMs) are artificial structures that exhibit unusual mechanical properties due to geometric arrangements rather than material properties of the constituents. This blossoming field takes advantage of modern fabrication techniques, from macroscale to the nanoscale to achieve unprecedented mechanical properties in many fronts, from auxetic elasticity to programmed nonlinear responses. A prominent new direction of MM is “topological mechanics” where topological states of matter are realized in mechanical systems, giving rise to highly robust properties. The objective of this research is to open up a new field of active topological mechanical metamaterials (TMMs) by (1) developing 3D printing and self-assembly systems to fabricate TMMs that are addressable at the nanoscale and scalable to the macroscale, (2) designing new classes of TMMs, especially ones featuring fractional excitations, taking advantage of recent advances in knowledge of quantum topological states, the vast majority of which remain uncharted territories for mechanics, (3) using artificial intelligence tools to design and realize continuous media TMMs with no open spaces, which greatly broaden the structural and functional attributes of TMMs compared to traditional cellular designs, and (4) applying the TMMs to realize unidirectional and backscattering-free propagation of waves at previously inaccessible frequency ranges.