Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 20: SYMPOSIUM Microfluidics I: Boundary conditions, manipulation, and transport
CPP 20.7: Vortrag
Donnerstag, 30. März 2006, 11:45–12:00, ZEU 160
Fluid transport in microchannels induced by high frequency travelling electric waves — •Maika Felten1, Magnus Jäger2, Peter Geggier2, and Claus Duschl1 — 1Fraunhofer-Institut für Biomedizinische Technik, Invalidenstraße 42, 10115 Berlin — 2Universität des Saarlandes, Ensheimer Straße 48, 66386 St. Ingbert
Presently, the handling of fluid volumes in the nanoliter range suffers from a lack of suitable pumping methods. This severely limits the impact of lab-on-chip applications in biotechnology and cell biology. For the creating of a fluid flow in microchannels, we use a combination of temperature fields and high-frequency electric fields that act on the fluid. The temperature field induces inhomogeneities of the permittivity and / or conductivity of the medium. Together with the electric field, this creates volume charges in the liquid bulk which in turn interact with the electric field. To induce a certain flow direction, the electric potential is applied as a sinus-shaped wave travelling parallel to the channel axis. The use of temperature fields is a versatile method to control the fluid flow. For this reason, we combine temperature fields generated by the Ohmic heating due to the electric field with external heating sources like Peltier elements and laser light. By these means, we are able to generate a directed net fluid flow but also highly complex streaming patterns. These streaming patterns can be used to mix tiny volumes in a laminar flow or to accumulate nanoparticles in stationary vortices.