Obstacle design for pressure-driven vector chromatography in microfluidic devices

A mechanism that breaks the symmetry of fluid flows in microfluidic arrays of obstacles and hence facilitates pressure-driven vector chromatography is introduced. The proposed mechanism allows a fraction of the flow to penetrate the obstacles, while the immersed particles are sterically excluded. Based on Lattice-Boltzmann simulations of the fluid flow, it is investigated how and to what extent the symmetry of the flow is broken. The key characteristics of the separation process are estimated by means of Brownian ratchet theory and validated with Brownian dynamics simulations.