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.
@article{arxiv.2102.10184,
title = {Submersed Micropatterned Structures Control Active Nematic Flow, Topology and Concentration},
author = {Kristian Thijssen and Dimitrius Khaladj and S. Ali Aghvami and Mohamed Amine Gharbi and Seth Fraden and Julia M. Yeomans and Linda S. Hirst and Tyler N. Shendruk},
journal= {arXiv preprint arXiv:2102.10184},
year = {2021}
}