AVS 47th International Symposium
    MEMS Thursday Sessions
       Session MM+BI-ThM

Paper MM+BI-ThM8
Integration of Microcapillary Electroporesis and Inductively Coupled Plasma Spectrometry for Rapid Biological/Chemical Analysis

Thursday, October 5, 2000, 10:40 am, Room 309

Session: Bio-MEMS and Microfluidics
Presenter: T. Ichiki, Toyo University, Japan
Authors: T. Ichiki, Toyo University, Japan
T. Koidezawa, Toyo University, Japan
R. Taura, Toyo University, Japan
T. Ujiie, Toyo University, Japan
Y. Horiike, The University of Tokyo, Japan
Correspondent: Click to Email
Rapid and sensitive elemental specification of trace amounts of samples are important for chemical, biological, environmental and clinical applications. For the goal of integration of microcapillary electrophoresis (µCE) and inductively coupled plasma (ICP) optical emission spectrometry (OES) on a chip, we have fabricated µmCE chips with a nebulizer, and have investigated conditions for generating microscale ICPs. Microcapillary and nebulizer patterns were etched onto the quartz plate in C@sub 4@F@sub 8@/SF@sub 6@ plasmas using Cr masks. The etched quartz plate was dipped in 1% diluted HF solution and then bonded together with the other quartz plate with drilled holes. These two plates were press-bonded under the load of 1.3 MPa at room temperature for 24 hours. Samples separated via electroosmotic and electrophoresis phenomena were nebulized by controlling the carrier gas flow around the nozzle located at the capillary end to achieve the injection of pico-liter droplets in the gas. Subsequently, generation of microscale VHF-ICPs was investigated. Discharge chambers of 500µm-5 mm depth and/or width were fabricated on 20 mm@super 2@ quartz plates, which was attached under the 70-mm-@phi@ circular quartz plate set on a small vacuum chamber. A 5-mm-@phi@ antenna was set on the circular quartz plate so as to locate just above the discharge chamber. The power for Ar plasma ignition and mode jump from E- to H-discharge was examined by means of spectroscopy. In the case of discharge chamber dimension of 5 mm width and more than 2 mm depth, the power for ignition was only 5 W at pressures of 0.01-1 Torr, while no mode changes were observed even at 100 W. When reducing the discharge chamber depth to 1-1.5 mm, mode change occurred around 10 W and emission intensity drastically increased by 100 times. Thus high density VHF-ICP was found to be easily attained when the characteristic length of the discharge space is around 1 mm and the pressure is 1-10 Torr.