Active matter is material driven out of equilibrium at the scale of individual constituents. Many well-studied synthetic examples are collections of self-propelled particles, where individuals consume fuel and do work on the environment. In this project we explore a minimal model of informationally driven active matter. This substance is not in equilibrium, despite doing no work on its surroundings.
When the constituents of a material interact with transverse, or non-central forces, topological defects spontaneously move under the influence of active forces present in the defect core. These topological defects control the plastic deformation of crystalline solids and their mechanical properties.
Large domains of crystalline material can be reshaped by the motion of topological defects known as dislocations. Dislocations in 2D colloidal crystals can be created in pairs by applying local stresses. In this project, we demonstrate how a small cluster of swellable particles can create and move dislocations, usefully reshaping a large crystalline cluster.
Excitable systems, such as the neurons in the brain, can undergo large excursions of a normally small internal variable in response to an external perturbation. In this project, we are studying how swarms of many agents can pass simple messages by excitable spiking that lead to collective organization and group behaviors.