DFG Priority Program SPP 1164
Nano- & Microfluidics:
Bridging the Gap between
Molecular Motion and Continuum Flow
From micropumps to nanopumps: Travellling wave-driven transport of fluids and particles through highly confined geometries – an experimental and theoretical approach
| Project Leader: | Magnus Jäger Universität des Saarlandes Fachrichtung 2.28 - Medizintechnik St. Ingbert |
| together with: | Prof. Dr. Michael Stuke Max-Planck-Institut für biophysikalische Chemie (Karl-Friedrich-Bonhoeffer-Institut) Göttingen |
Summary
Many microfluidic applications rely on external pumps for liquid
transport through microchannels. The major disadvantages of such
macroscopic pumps are: (1) their use is limited to micron-sized
geometries because of the high pressures that are necessary to overcome
the hydrodynamic resistance of nanocapillaries and (2) their temporal
velocity profile is not constant but inherently periodic. The latter
not only applies to peristaltic pumps but also to common syringe pumps.
Here, we investigate an alternative concept: linear arrays of
microelectrodes are fed with phase-shifted high frequency voltage
signals so that a travelling electric field is generated. The resulting
travelling wave (TW) acts on gradients of the polarisability of the
liquid and exerts a force on it, which consequently results in a flow.
One important advantage of TW pumping is its inherent suitability for
miniaturisation because the flow is not effected by a pressure gradient
but by a force that directly acts on the whole fluid volume.
Within the first funding period of this project, we applied a combination of experimental and theoretical approaches to develop a variety of microfluidic systems for investigating stable and well-defined TW pumping in microchannels. Already now, less than one and a half years after start of the project, we can present substantial results.
Taking our successes of the first 1.5 years as a starting, we will now advance by addressing the following main points, several of these in collaboration with other participants of the Programme: (1) miniaturisation of our structures into the nano-range, (2) elaborate experimental and theoretical approaches towards mixing on the micro- and nanoscale, (3) increase of the range of available flow rates by use of materials with excellent thermal conductivity, (4) application of TW pumping to the manipulation of surface-bound macromolecules, like DNA (5) velocimetry by correlation spectroscopy, (6) enhancing TW pumping by temperature gradients induced and stabilised by laser illumination. Due to the strong expertise of the teams assembled in this project, we rate the prospects for further scientific progress and the transition from “micro” to “nano” very high. TW pumps represent a unique combination of nanoscience and technologically relevant applications.
Within the first funding period of this project, we applied a combination of experimental and theoretical approaches to develop a variety of microfluidic systems for investigating stable and well-defined TW pumping in microchannels. Already now, less than one and a half years after start of the project, we can present substantial results.
Taking our successes of the first 1.5 years as a starting, we will now advance by addressing the following main points, several of these in collaboration with other participants of the Programme: (1) miniaturisation of our structures into the nano-range, (2) elaborate experimental and theoretical approaches towards mixing on the micro- and nanoscale, (3) increase of the range of available flow rates by use of materials with excellent thermal conductivity, (4) application of TW pumping to the manipulation of surface-bound macromolecules, like DNA (5) velocimetry by correlation spectroscopy, (6) enhancing TW pumping by temperature gradients induced and stabilised by laser illumination. Due to the strong expertise of the teams assembled in this project, we rate the prospects for further scientific progress and the transition from “micro” to “nano” very high. TW pumps represent a unique combination of nanoscience and technologically relevant applications.