Simulation of the transport of biological cells in the microfluidic device

We developed a computer-aided methodology - the Bio-Particle (BP) simulation technique - for the general particle movement in Lab-On-A-Chip devices. This has also been validated with experiments on biological cells (3T3 cell; diameter 10 nm). The cell motion under steady flow was calculated by applying the one-way coupled Lagrangian method. The equation of motion consists of multiple force terms, i.e. drag, pressure gradient, Brownian random, and gravitational forces. By solving the governing equation with the Rosenbrock method based on an adaptive time-stepping technique, the cell trajectory can be solved over a prescribed 3D microfluidic device model. Moreover, each cell was assumed to be a solid sphere with adjustable elasticity, while the physical interactions between cells and device structures were also considered, particularly when cells sediment in the cell trapping sieves. Cells were trapped in these apertures where hydrodynamic forces were strong enough to resist cell movements. The result of experiment showed good agreement with that of the corresponding simulation. Finally, we have achieved an optimized structure of cell trapping chamber which showed the most enhanced cell trapping capability by using the Bio-Particle (BP) simulation technique.