Tuning finely the packing density of heavy microparticles in a microfluidic channel

Abstract

The packing of granulates inside microfluidic channels is important for applications of liquid chromatography and bead based immunoassays. In such applications, the granular packing acts as a porous medium, and properties like pours size, homogeneity, and regularity determine the performance of the device. In this work we show that the packing density of iron micrometric particles can be finely tuned inside a microfluidic channel by applying a vibration protocol originally developed for macroscopic, dry granular systems. Our results suggest that much of what is known about the physics of compaction in macroscopic granular matter could be applied to better control packings inside microchannels with important implications for applications.