Paradoxical Brownian motion in a microfluidic device: Absolute negative mobility
Condensed Matter Theory, Bielefeld University, Bielefeld, Germany
2 Experimental Biophysics & Applied Nanoscience, Bielefeld University, Bielefeld, Germany
We report on a paradoxical migration mechanism in a microstructured lab-on-a-chip environment. The phenomenon is based on a subtle interplay between Brownian motion (thermal noise), a periodic and symmetric microstructure, and a biased AC electric field. The resulting non-linear dynamics far from thermal equilibrium gives rise to absolute negative mobility, i.e. a migrational transport, which is – both for negative and positive bias – always opposite to the net acting force, in good agreement between experiment and theory.
© EDP Sciences, Springer-Verlag, 2007