Speaker
Ms
Aleksandra Slapik
(University of Silesia)
Description
Dynamics of the systems at the sub-micro level can reveal astounding effects and may often mislead our intuition. However, since fluctuations play a key role at this scale, unexpected physical phenomena that contradict our everyday experience should not be a surprise. In this study we consider one of the anomalous transport effects, namely the directed transport of the particles in the opposite direction to an external static force applied to the system. Such a behaviour, referred to as negative mobility, was predicted theoretically in 2007 in a system consisting of inertial Brownian particle moving in a one-dimensional periodic symmetric potential [1]. A year later it was confirmed experimentally in the experiment involving determination of current-voltage characteristics of the microwaved-driven Josephson junction [2]. In 2010 negative mobility has been observed for sub-micro colloidal particles [3] and in 2016 for intracellular organelles [4].
In terms of the Brownian motion the following problem is considered: is it possible to use negative mobility in order to mechanically separate a mixture of various particles in a controlled manner? A number of experiments involving negative mobility already report on successful separation of two types of particles with different sizes in a microfluidic devices [3, 4]. However, no investigation on how to isolate particles with desired parameters has been found. We performed a number of numerical simulations in order to reveal conditions that guarantee controlled particles isolation by the means of difference in their mobility. In the mechanism proposed here the distinction between particles is based on their absolute mass, i.e. parameter of the model reflecting the correlation between particle mass, applied potential and friction forces
present in the system.
[1] L Machura, M Kostur, P Talkner, J Luczka, and P Hanggi. Absolute negative mobility induced by thermal equilibrium fluctuations. Physical Review Letters, 98(4):040601, 2007
[2] J Nagel, D Speer, T Gaber, A Sterck, R Eich-horn, Peter Reimann, K Ilin, M Siegel, D Koelle, and R Kleiner. Observation of negative absolute resistance in a josephson junction. Physical Review Letters, 100(21):217001, 2008
[3] Ralf Eichhorn, Jan Regtmeier, Dario Anselmetti, and Peter Reimann. Negative mobility and sorting of colloidal particles. Soft Matter, 6(9):1858–1862, 2010.
[4] Jinghui Luo, Katherine A Muratore, Edgar A Arriaga, and Alexandra Ros. Deterministic absolute negative mobility for micro-and submicrometer particles induced in a microfluidic device. Analytical Chemistry, 88(11):5920–5927, 2016
Primary author
Ms
Aleksandra Slapik
(University of Silesia)
Co-authors
Dr
Jakub Spiechowicz
(Institute of Physics, University of Silesia in Katowice)
Prof.
Jerzy Łuczka
(University of Silesia, Katowice)
