Rate Controlled Reconfiguration of Topological Linkages

Nonlinear structural transformations are typically actuated via either a global excitation that leads to a homogeneous, rate-controlled transformation (e.g. origami), or a local excitation leading to a heterogeneous, cascade-like transformation that propagates at an uncontrolled rate (e.g. buckling systems). In this talk, we present a design framework for linkages that exhibit the best of both worlds: transformations from local excitations with full rate-control. We focus on a specific type of linkages referred to as triangle chains, which host a non-linear, heterogeneous mechanism known as a soliton. This soliton can be propagated to reconfigure the chain through movement of a localized soft mode between ends of the chain. We selectively introduce energy-providing elements to offset realistic losses associated with the soliton's propagation, thereby completely controlling the soliton's profile in both space and time. These designs are then verified through both molecular dynamics simulations and experiments with physical prototypes.