Three-dimensional diamagnetic particle deflection in ferrofluid microchannel flows

Litao Liang, Junjie Zhu, Xiangchun Xuan

Research output: Contribution to journalArticle

46 Scopus citations

Abstract

Magnetic field-induced particle manipulation is a promising technique for biomicrofluidics applications. It is simple, cheap, and also free of fluid heating issues that accompany other common electric, acoustic, and optical methods. This work presents a fundamental study of diamagnetic particle motion in ferrofluid flows through a rectangular microchannel with a nearby permanent magnet. Due to their negligible magnetization relative to the ferrofluid, diamagnetic particles experience negative magnetophoresis and are repelled away from the magnet. The result is a three-dimensionally focused particle stream flowing near the bottom outer corner of the microchannel that is the farthest to the center of the magnet and hence has the smallest magnetic field. The effects of the particle's relative position to the magnet, particle size, ferrofluid flow rate, and concentration on this three-dimensional diamagnetic particle deflection are systematically studied. The obtained experimental results agree quantitatively with the predictions of a three-dimensional analytical model.

Original languageEnglish (US)
Article number034110
JournalBiomicrofluidics
Volume5
Issue number3
DOIs
StatePublished - Sep 20 2011

Fingerprint Dive into the research topics of 'Three-dimensional diamagnetic particle deflection in ferrofluid microchannel flows'. Together they form a unique fingerprint.

Cite this