Viscoelastic Metamaterials

We show how viscoelasticity can be harnessed to increase functionality in mechanical metamaterials. First, we explore experimentally the mechanical snap-through response of metamaterials that are made of constituents that exhibit large viscoelastic relaxation effects, encountered in the majority of rubbers [1]. Second, we demonstrate that we can rationally design multimode mechanical metamaterials, featuring viscoelastic and elastic elements. By altering the loading rate, we can switch between the two modes of deformation. Our findings bring a novel understanding of metamaterials in the dynamical regime and opens up avenues for the rational design of multifunctional viscoelastic metamaterials.

[1] Dykstra, D. M. J., Busink, J., Ennis, B., and Coulais, C. "Viscoelastic Snapping Metamaterials." J. Appl. Mech. November 2019; 86(11): 111012. https://doi.org/10.1115/1.4044036