Simulating Vesicle Deformations Under Fluid Flow

Self-propelled microrobots have the potential for use as carriers and probes in narrow spaces and channels (Alapan et al, 2019). They can potentially deliver drugs and diagnose disease, but their functionality depends on the deformation and mobility of them. In this work, we develop theoretical models to quantify vesicle deformation under fluid flows by modeling the vesicle as a layer of solid structure with low elasticity. The fluid is modeled as a Newtonian flow. The Fluid-Structure Interaction Modulus in COMSOL Multiphysics is used for numerical simulation where a vesicle sits in a fluid-filled channel. In the model, a shear velocity is applied to a horizontal inlet at the top of a channel, which is modeled as infinitely long by imposing period boundary conditions. The horizontal flow will generate laminar flows, which deforms the vesicle. The vesicle deformation will be quantified as a function of the flow rate, the viscosity of the fluid, the height of the channel, and the Young\u27s Modulus of the vesicle. In addition to the deformation, we will also quantify the shear stress on the vesicle from the flow