Microfluidics and Nanofluidics

, Volume 6, Issue 4, pp 521–527 | Cite as

Effect of relative particle size on large particle detachment from a microchannel

  • Nimisha Shukla
  • Kimberly H. Henthorn
Research Paper


The detachment of a single rigid sphere in a cylindrical PDMS microchannel has been investigated for systems where the particle occupies greater than 50% of the channel cross-sectional area. The fluid velocity required to detach a particle adhering to a microchannel wall is a function of many variables; however, only the effect of particle size is considered in this paper. Experiments were performed for Reynolds numbers less than 0.1, and the ratio of particle diameter, d p, to channel dimension, D, was varied from 0.50 to 0.95 in a 230 μm channel. A nonionic surfactant (Tween 80) was used to minimize the effect of adhesive forces other than van der Waals forces. In addition, a simple force-balance model based on particle lift, buoyancy, drag, gravitational forces, and adhesion due to van der Waals forces has been developed to predict the velocity required for particle detachment. The predicted and experimentally measured velocities agree relatively well within the limit of experimental error. The detachment velocity was qualitatively found to increase with decreasing d p /D.


Particle Detachment PDMS Adhesion 



This work was sponsored by the University of Missouri Research Board (Grant #2103) and Mo-Sci Corporation (Rolla, MO, USA).


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  1. 1.Department of Chemical and Biological EngineeringMissouri University of Science and TechnologyRollaUSA

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