Mechanism of Clogging in Microfluidic Devices*

Clogging is a sudden interruption of flow in microparticle suspensions accompanied by aggregation of particles that occurs in many applications ranging from filtration media to microfluidic devices. While a comprehensive understanding of this process is essential to regulating and preventing clogging in these systems, the microscopic mechanisms underlying clog formation remain elusive. The rate of clog formation is, however, known to be determined by the ratio of the particle size to the constriction size and other factors including the presence of particle-surface and particle-particle adhesion. Complemented by high-speed imaging of microfluidic experiments, we develop a computational model of clog formation that accounts for hydrodynamic and steric surface interactions. Pore scale simulations of flowing suspensions through constrictions are used to analyze the formation of clogged structures. We also analyze the stability of the resulting configurations for a range of geometries. The effect of additional influences such as adhesion and prospects for control will be discussed.