AVS 49th International Symposium
    Microelectromechanical Systems (MEMS) Wednesday Sessions
       Session MM-WeP

Paper MM-WeP4
Development of Microfluidic Devices for Gas Centrifuge Separation

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Poster Session
Presenter: S. Li, University of Maryland
Authors: S. Li, University of Maryland
R. Ghodssi, University of Maryland
Correspondent: Click to Email
A mass spectrometer on a chip (MSOC) is suited for environmental monitoring with the advantages of fast response, low power consumption and portability. Gas centrifuge separation (GCS) is capable of concentrating the minor constituents in a gas mixture and increasing the sensitivity of MSOC. An integrated MEMS fabrication method is presented for developing GCS devices as the front-end for MSOC. A hybrid device that incorporates silicon, plastic and glass is realized by utilizing a combination of deep reactive ion etching (DRIE) and low temperature wafer bonding techniques. Inlet and outlet ports (500 µm in diameter and depth) are created in the silicon substrate by DRIE. Using standard photolithography, micro converging-diverging nozzles with throats as small as 3.2 µm wide and 5 µm deep are formed in EPON SU-8 supported on the silicon substrate. The second SU-8 layer, coated on a pyrex wafer, is bonded with the first SU-8 layer to form sealed micro nozzles. Macroscale capillary needles (400 µm in diameter) and quick-setting glue are used to interface the microfluidic device to the macroscopic world (i.e., the pressure measurement setup). Measures are taken to prevent the glue from seeping through the gaps and blocking the microfluidic channels. Calibration results demonstrate the feasibility of the test setup for measuring pressure distributions of gas flow in the micro nozzles. Preliminary measurement results and a detailed fabrication process will be presented.