Theory of electrohydrodynamic effects in microfluidics
Contacts:
Henrik Bruus, DTU Nanotech, 4525-6399 (Henrik.Bruus@nanotech.dtu.dk)
http://www.nanotech.dtu.dk/microfluidics
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| A sketch of the complex flow pattern (left) and the electric potential (right) that are generated in an electrolyte above an array of metal electrodes (black) biased with an ac voltage in the kHz range and with an amplitude up to 2 V. |
Microfluidics deals with the flow of liquids in systems of length scales typically in the range from 100 nm to 1 mm. As experimental tools have been refined the previous decade, a range of new phenomena has been discovered, which are not yet fully understood from a theoretical point of view.
An important class of problems relates to the behavior of electrolytes (salt water) influenced by external electric fields, ie., the role of electrokinetics in hydrodynamics. Because practically all biofluids are aqueous solutions of ions, the study of electrokinetic problems plays a central role in the development of the so-called lab-on-a-chip systems, where entire biochemical analysis laboratories are shrunk and put the surface of a silicon or polymer microchips.
In this theoretical and numerical project you will get to work as part of our research group on the theory of electrohydrodynamics for various experimentally observed phenomena, such as the electrokinetic micropump sketched in the figure. You will get to apply what you have learned or are about to learn in your courses on mechanics, thermodynamics, electromagnetism and nanotechnology. Moreover, you will get the opportunity to get aquainted with the general software for solving coupled, non-linear, partial differntial equations, COMSOL. The goal is to provide a basic theoretical physics explanation of the observed phenomena.