Microfluidics research group
Professor Lars R. Sætran
Rahel G/W. Negera
Piotr Domagalski (visiting graduate student)
Design, fabrication and functionality of Micro-Electro-Mechanical Systems (MEMS) is a multidisciplinary research field, combining branches of physics such as electronics, mechanics, optics and fluid dynamics with chemistry and biology, to mention a few. Due to their small sizes and large surface area-to-volume ratios, along with other inherent characteristics, the observed physical behavior of a microfluidic system does not always agree with predictions made using conventional 'large-scale', or continuum models, such as the Navier-Stokes equations for fluid flow. It is therefore desirable to investigate flow phenomena occurring in microfluidic devices experimentally in order to gain insight into this 'new physics' and, if possible, utilize these quantitative observations in the development of new theoretical and empirical models for micro-scale flow phenomena.
A micro-PIV system has been recently developed in our laboratory facilities. The system is composed of a high resolution Kodak MEGAPLUS ES1.0/10bit CCD camera, a RoadRunner framegrabber from BitFlow, an Olympus BX51 (modified) microscope, and a PHD2000 Infuse/Withdraw syringe pump. Two optically connected, pulsed Nd:YAG lasers are used for flow illumination. For a schematic illustration of the system, click here . If transparent microchips are to be investigated, the micro-PIV system can be easily modified into a forward-scatter configuration employing either laser light or white/filtered light.
What is micro-PIV?
Particle Image Velocimetry (PIV) is a well-established measurement technique for macroscopic flows, and is extensively described in the literature. Micro-PIV is a modification of PIV in order to access the small scales of micro-fluidic devices. The first successful micro-PIV experiment was conducted by Santiago et al. (1998), where the velocity field in a Hele-Shaw flow around a 30 micron elliptical cylinder was recorded. The system utilized a CCD camera, an epi-fluorescent microscope equipped with color filters, seeding particles tagged with a fluorescent dye, and a Hg-arc lamp to illuminate the flow continuously. A year later, Meinhart et al. (1999) demonstrated a micro-PIV system consisting of the same general components with the exception that the continuous light source was replaced by two pulsed Nd:YAG lasers. The technique was applied on a microchannel flow, and results with high spatial resolution and -accuracy were reported.
The working principles of our micro-PIV system are illustrated here:
Working principle of micro-PIV : step-by-step animated demonstration.
Mielnik, M.M. & Sætran, L.R. Selective Seeding for micro-PIV Experiments in Fluids (in press).
Solli, L.A., Mielnik, M.M., Karlsen, F., Sætran, L. & Furuberg, L. Flow visualization and simulation of discrete liquid droplets moving in micro-channels. Proc. MekIT'05 Third national conference on computational mechanics, 11 - 12 May, 2005, NTNU, Trondheim, Norway.
Mielnik, M., Ekatpure, R., Sætran, L. & Schönfeld, F. Comparison of micro-PIV and CFD flowfield analysis of a crossflow microfiltration device - measurement depth considerations. Proc. PIVNET II / ERCOFTAC Intl. Workshop on Micro - PIV and Applications in Microsystems, 7 - 8 April, 2005, Delft University of Technology, The Netherlands.
Mielnik, M., Ekatpure, R., Sætran, L. & Schönfeld, F. Sinusoidal crossflow microfiltration device - experimental and computational flowfield analysis. Lab On a Chip, 2005, 5, 897 - 903.
Anja Gulliksen, Lars Solli, Klaus Stefan Drese, Olaf Soerensen, Frank Karlsen, Henrik Rogne, Eivind Hovig, Reidun Sirevaag, Parallel nanoliter detection of cancer markers using polymer microchips, Lab on a Chip, DOI: 10.1039/b415525d (2005).
Mielnik, M. & Sætran, L. Micro Particle Image velocimetry - an overview. Turbulence 10, pp. 83 - 90, 2004. Presented at the Intl. Workshop on size effects in microfluidics and heat transfer - fundamental and practical aspects, Kielce, Poland, September 16, 2004.
Mielnik, M., Pedersen, G. & Sætran, L. Criteria for droplet generation in a microchannel network. Proc. Transport Phenomena in Micro and Nanodevices, ed: Gad-el-Hak, M., Kailua - Kona, USA, 17 - 21 October, 2004.
Gulliksen, A., Solli, L., Karlsen, F., Rogne, H., Hovig, E., Nordstrøm, T., Sirevåg R., Real-Time Nucleic Acid Sequence-Based Amplification in Nanoliter Volumes. Anal. Chem., 2004, 76, 9-14.
Liv Furuberg, Dag Wang, Andreas Vogl and Lars Solli, Flowsensor for dosing applications and microfluidics at SINTEF, Micro Structure Workshop 2004 (MSW 2004), Ystad, Sweden, March 2004.
Drese, K. S., Solli, L., Sörensen, O., Gulliksen, A., Design and realization of a Lab-on-a-Chip system for multiple real-time detection of Nucleic Acid Sequence-Based Amplification (NASBA), smallTalk 2003, San Jose, CA, USA.
Mielnik, M. & Sætran, L. Micro-PIV investigation of a sinusoidal crossflow microfiltration module. Proc. 1st International Conference on Microchannels and Minichannels, ed: Kandlikar, S.G., pp. 887 - 894, Rochester, USA, April 24 - 25, 2003.
Anja Gulliksen, Lars Solli, Frank Karlsen, Reidun Sirevåg and Henrik Rogne, Detection of multiple real-time NASBA in nanoliter volume, Proc. of the mTAS Symposium (mTAS 2002), Nara, Japan, pp. 184-186, 2002.
Solli, L., Gulliksen, A., Nordstrom, T., Sirevåg R., Rogne, H., Detection of real-time NASBA in a 10 nl silicon – glass microchip. Eurosensors XVI, The 16th European Conference on Solid-State Transducers, September 15-18, Prague, Czech Republic, 2002.
Theses and reports:
Lunde, I. Characteristics of hydrodynamically generated particle sheet for micro-PIV applications, M.Sc. pre - project, Dept. of Energy and Process Engineering, NTNU, 2005.
Aker, I. Droplet generation in a microchannel network: prediction and control, M.Sc. thesis, Dept. of Energy and Process Engineering, NTNU, 2005.
Mielnik, M. Micro-PIV and its application to some BioMEMS related microfluidic flows. Doctoral thesis no. 2005:44, Dept. of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway, 2005. ISBN 82-471-6956-8 (printed version), ISBN 82-471-6954-1 (electronic version).
Aker, I. Droplet generation in a microchannel network: prediction and control, M.Sc. pre - project, Dept. of Energy and Process Engineering, NTNU, 2004.
Pedersen, G. Dynamics of drops in microscale flow, MSc Thesis, Dept. of Energy and Process Engineering, NTNU, 2004.
Pedersen, G. Electrokinetic flow and instabilities in microchannels with a uniform Zeta-potential. M.Sc. pre - project, Dept. of Energy and Process Engineering, NTNU, 2003.
Laboratory for Turbulence and Complex Flow , University of Illinois at Urbana-Champaign
(these pages are forever under construction, more links and info to come...)
Any comments regarding the contents of this page and microfluidic research in general are highly appreciated!