A Multifaceted Study of Nematic Order Reconstruction in Microfluidic Channels

SIAM Journal on Applied Mathematics, Volume 83, Issue 6, Page 2284-2309, December 2023.
Abstract. We study order reconstruction (OR) solutions in the Beris–Edwards framework for nematodynamics, for both passive and active nematic flows in a microfluidic channel. OR solutions exhibit polydomains and domain walls, and as such, are of physical interest. We show that OR solutions exist for passive flows with constant velocity and pressure, but only for specific boundary conditions. We prove the existence of unique, symmetric, and nonsingular nematic profiles for boundary conditions that do not allow for OR solutions. We compute asymptotic expansions for OR-type solutions for passive flows with nonconstant velocity and pressure, and active flows, which shed light on the internal structure of domain walls. The asymptotics are complemented by numerical studies that demonstrate the universality of OR-type structures in static and dynamic scenarios.