How to program the mechanics of frustrated and floppy metamaterials

Achieving advanced mechanical tasks in simple, scalable geometric structures is a daunting challenge for materials science. In this talk, I will discuss two complementary routes to achieve programmable mechanical tasks: (i) in frustrated metamaterials: I will discuss how topological solitons can be manipulated to achieve non-abelian mechanics; (ii) in floppy metamaterials: I will discuss how dissipation and gain can be used to control deformation pathways. Specifically I will illustrate how viscoelasticity can be used to achieve strain-rate dependent properties and how non-reciprocal gain can be used to create unusual responses to impacts.