From activity induced anchoring to wetting in liquid-liquid phase separation

We combine conventional equilibrium liquid-liquid phase separation with a microtubule-based active system. The microtubules strongly compartmentalize into one of the two coexisting phases where they generate autonomous chaotic flows. The interaction between the autonomous flows and the soft and deformable interface leads to unique properties and structures that are not accessible in conventional equilibrium systems. We study activity-induced wetting phenomenon near a rigid wall. Non-uniform distribution of active stress leads to coherent force pushing the interface against gravity and surface tension. We seek an explanation using active anchoring theory and test it by measuring the 3D director field with new optical techniques. By further designing various dimensionalities and geometries, we explore the transition from spontaneous turbulent flows into controllable directional movements. Our result opens a route towards constructing out-of-equilibrium soft materials with life-like functionalities.