Anton Souslov

Active solids and the elastic Leidenfrost effect

Active solids consume energy to allow for actuation and shape change not possible in equilibrium. In this talk, I will overview the elasticity of systems as wide-ranging as far-from-equilibrium hydrogels, nanoparticles, and mechanical structures composed of active robotic components. These results provide theoretical underpinning for recent experiments and point to the design of novel soft machines. I will focus on our recent work on hydrogel spheres being lowered onto a hot plate [1]. As the bottom vaporises, the resulting flow couples tightly to elastic deformations within the sphere, giving either spontaneous bouncing or steady-state floating as manifestation of the so-called elastic Leidenfrost effect. I will present theory and simulations of the floating case, which demonstrate a remarkable phenomenon: the heavier the solid, the higher it floats.

[1] Binysh et al. Thermodynamic lubrication in the elastic Leidenfrost effect. arXiv:2207.02769