A hallmark of living systems is their ability to consume energy from the environment to sustain function. The largest gap between living and synthetic material systems lies in autonomy, leading to a growing interest in active matter – materials that consume energy to drive their out-of-equilibrium dynamics. While the vast majority of well-studied active materials are fluid-like, we focus on active solids.
A major inspiration for our work is the Belousov-Zhabotinsky (BZ) reaction, a chemical oscillator that can be embedded into polymer gels to create materials that swell and contract autonomously, without external intervention. We study BZ gels as a model system for active solids: materials that transduce chemical energy directly into mechanical motion. By coupling reaction-diffusion dynamics with the mechanics of elastic solids, these systems exhibit rich behavior including traveling waves, spontaneous oscillations, and pattern formation. Our work explores how geometry and material design can be used to direct and control this activity, with a long-term vision of materials that sense, compute, and actuate in a fully autonomous fashion.
I. Levin, R. Deegan, and E. Sharon, Self-Oscillating membranes: chemo-mechanical sheets show autonomous periodic shape-transformation. Phys. Rev. Lett. 2020 125(17)