Submersed Micropatterned Structures Control Active Nematic Flow, Topology and Concentration

TL;DR

This paper introduces a novel, tunable method using submersed micropatterned structures to control flow, topology, and composition in active nematic films, enabling non-intrusive engineering of active microfluidic systems.

Contribution

It demonstrates a new approach to manipulate active fluids through indirect rheological coupling via micropatterned structures, offering precise control over flow and topology.

Findings

Micropatterned structures create virtual boundaries in active nematic films.

The method allows for non-intrusive, position-dependent control of active fluid dynamics.

Simulations confirm effective dissipation control through submersed structures.

Abstract

Coupling between flows and material properties imbues rheological matter with its wide-ranging applicability, hence the excitement for harnessing the rheology of active fluids for which internal structure and continuous energy injection lead to spontaneous flows and complex, out-of-equilibrium dynamics. We propose and demonstrate a convenient, highly tuneable method for controlling flow, topology and composition within active films. Our approach establishes rheological coupling via the indirect presence of fully submersed micropatterned structures within a thin, underlying oil layer. Simulations reveal that micropatterned structures produce effective virtual boundaries within the superjacent active nematic film due to differences in viscous dissipation as a function of depth. This accessible method of applying position-dependent, effective dissipation to the active films presents a non-intrusive pathway for engineering active microfluidic systems.