Most MEMS (microelectromechanical system) devices are made of silicon which is transparent at infrared wave-lengths. Utilizing this infrared transparency of silicon, infrared thermal velocimetry was developed to measure the velocity in MEMS based fluidic devices. The method uses an infrared laser to generate a short heating pulse in a flowing liquid. An infrared camera records the radiative images from the heated flowing liquid and the steady flow velocity is obtained from consecutive radiative images. A wide range of the velocity (1 cm/s-1 m/s or higher) in silicon (or other materials that are transparent to infrared radiation) microchannels can be measured. Numerical simulations have been carried out and are in good agreement with the experiments. Parametric studies have been carried out for different channel dimensions and laser characteristics.
Bibliographical noteFunding Information:
Manuscript received July 17, 2002; revised December 10, 2002. This work was supported by the Defense Advanced Research Projects Agency (DARPA) under the HERETIC program. Subject Editor W. N. Sharpe, Jr. The authors are with the Department of Mechanical Engineering, University of California, Berkeley, CA 94720-1740 USA (e-mail: cgrigoro@me. berkeley.edu). Digital Object Identifier 10.1109/JMEMS.2003.811753
- Flow measurement
- Microfluidic device
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering