Abstract
Recently, the counter intuitive migration phenomenon of absolute negative mobility (ANM) has been demonstrated to occur for colloidal particles in a suitably arranged post array within a microfluidic device [1]. This effect is based on the interplay of Brownian motion, nonlinear dynamics induced through microstructuring, and nonequilibrium driving, and results in a particle movement opposite to an applied static force. Simultaneously, the migration of a different particle species along the direction of the static force is possible [191, thus providing a new tool for particle sorting in microfluidic device format. The so far demonstrated maximum velocities for micrometer-sized spheres are slow, i.e., in the order of 10 nm per second. Here, we investigate numerically, how maximum ANM velocities can be significantly accelerated by a careful adjustment of the post size and shape. Based on this numerical analysis, a post design is developed and tested in a microfluidic device made of PDMS. The experiment reveals an order of magnitude increase in velocity.
Original language | English (US) |
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Pages (from-to) | 1461-1467 |
Number of pages | 7 |
Journal | Journal of Separation Science |
Volume | 30 |
Issue number | 10 |
DOIs | |
State | Published - Jul 2007 |
Externally published | Yes |
Keywords
- Absolute negative mobility
- Microfluidics
- Separation
ASJC Scopus subject areas
- Analytical Chemistry
- Filtration and Separation