Coarsening dynamics of a liquid crystal biosensor: Effects of adsorbed nanoparticles, flow and thermal fluctuations

We explore the coarsening dynamics of a model for experimental liquid-crystal (LC) biosensors for viral particles: a thin film of LC confined between two parallel, aligning substrates, after a quench into the nematic phase. In the absence of particles, the LC undergoes a coarsening process that ultimately produces a uniform orientation state. By contrast, when the surface coverage c exceeds a critical value, the dynamics is slowed down and the system exhibits multidomain behavior, characterized by a finite correlation length for the tensor order parameter. In this work, we use (a) a dynamic field theory to study the dependence of the critical coverage c with operational parameters of the biosensor, such as the scalar order parameter, the separation between substrates, and the adsorption pattern; and (b) a fluctuating LC lattice Boltzmann method that allows the exploration of the effects that hydrodynamics and thermal fluctuations have on the coarsening process and the critical concentration in 3D.