Design considerations for robust suspension-based microfluidic systems for biomedical applications

Polymer microspheres are commonly used in microfluidic devices for biomedical applications. However, the presence of these particles can compromise the reliable operation of the microfluidic devices, as particles have been observed to deposit successively until they block a flow passage, which then leads to device failure. This paper presents investigations of the mechanics of particle deposition to give a better understanding of the process leading to subsequent device failure. Our measurements and observations show that commercially available suspensions can have a high polydispersity, and that a low concentration of relatively large particles can have a major effect on the mean time to failure of a microchannel through blockage by particles.