Modeling of red blood cell deformation in a microchannel driven by traveling surface acoustic waves

The static deformation of red blood cells in a microfluidic channel driven by traveling surface acoustic wave (SAW) is theoretically and numerically investigated. The computational framework takes into account the coupling effect of acoustic and mechanic, that is, the propagating acoustic wave generates steady acoustic radiation stress to deform the cell and in turn the deformed cell reshapes the acoustic field. Specifically, the acoustic field is calculated by using a simplified fluid model, which includes the fluid domain with simplified boundary conditions representing the surrounding solids, and the cell is modeled as an elastic biological membrane enclosing with a homogenous fluid. Results show that the SAW generates periodically distributed acoustic pressure nodes in the customized fluid channel, where the cell is predicted to be trapped. The trapped cells are observed to be oriented with their flat nearly perpendicular to the device substrate and stretched along the propagation direction of the SAW, which is consistent with the experimental observations. The parallel cell manipulation is further simulated to illustrate the high-throughput characteristics of the acoustic deformation method. The present computational model is helpful to extract the mechanical properties of cells accurately and design the acoustic microfluidic channel to detect cells reasonably.