Chemistry: electrical and wave energy – Apparatus – Coating – forming or etching by sputtering
Patent
1988-04-12
1990-01-02
Niebling, John F.
Chemistry: electrical and wave energy
Apparatus
Coating, forming or etching by sputtering
73 231, 73 611C, G01N 2726, G01N 3002, G01N 3062, G01N 3064
Patent
active
048911208
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a chromatographic separation device. It relates particularly to the provision of such a device that can be used for a variety of applications such as electrolysis, chromatography, electrophoresis and the study of electrokinetic phenomena.
The development of separation technology has brought with it the need to be able to work accurately with very small test samples and possibly to provide a separation cell that can be integrated with a detection system. The signals from an integrated sensor will be less likely to be influenced by noise or leakage as compared with those of a discrete sensor. The sensing element would thus make use of a non-specific technique such as conductivity, optical (absorbance, refractive index) or electrochemical properties or, more likely, a suitable combination of these.
The present invention was devised to provide a separation device that was capable of being manufactured in a miniature form to assist the microseparation and detection of biochemical and other chemical species.
According to the invention, there is provided a chromatographic separation device comprising a body of a semiconductor material which body has a longitudinal channel formed in a surface thereof, the channel being capable of containing a predetermined volume of a liquid or solid material for a chromatographic test or separation procedure, the channel carrying at least one electrode positioned intermediate the channel ends.
Preferably, an open side of the said channel is closed by a cover plate.
The channel may be formed by an integrated circuit technique such as photolithography and micromachining. Alternatively, the channel may be formed by a micromechanical machining technique such as electromechanical sawing.
The body of semiconductor material may be a silicon wafer. The separation device may further carry an electronic or optical sensor element which is located in line with the channel. The body of semiconductor material may be provided with two or more of the longitudinal channels, the channels being located in a mutually parallel arrangement.
By way of example, some particular embodiments of the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view greatly enlarged of an anisotropically etched microchannel structure in a body of silicon wafer material;
FIG. 2 is a similar view showing a different channel shape;
FIG. 3 is a similar view showing the result of etching a body of silicon having a different crystal orientation;
FIG. 4 is a similar view showing the result of an isotropic etching process;
FIG. 5 is a plan view showing the formation of a channel having a serpentine shape by the etching process;
FIG. 6 is similar to FIG. 4 and shows the result of an electromechanical sawing process;
FIG. 7 is a cross-sectional view showing a metal contact pattern deposited on a channel;
FIG. 8 is a similar view showing the metal contact pattern having been etched or sawed to partially remove the metal deposit;
FIG. 9 is a plan view of the electrode structure depicted in FIG. 8;
FIG. 10 is a cross-sectional view of the electrode structure on a channel with a cover plate placed over the channel;
FIG. 11 is a plan view of a silicon wafer provided with four chromatographic separation devices of the invention and an array of electronic or optical sensors;
FIG. 12 is a graph showing the results of some conductance measurements made using the separation devices;
FIG. 13 is a plan view showing a prototype construction of a single ended chromatographic separation device; and,
FIG. 14 is a similar view of a double ended separation device.
The construction of the chromatographic separation device of the invention begins with the preparation of a slice of semiconductor material and in the embodiment about to be described this was a silicon wafer. For convenience in use of the separation device some of the test slices were formed with two channels located in a mutually parallel arrangement.
The formation of very narrow channels in sili
REFERENCES:
patent: 3149941 (1964-09-01), Barnitz et al.
patent: 3465884 (1969-09-01), Matherne
patent: 3503712 (1970-03-01), Sussman
patent: 3538744 (1970-11-01), Karasek
patent: 3932264 (1976-01-01), Haruki et al.
patent: 4462962 (1984-07-01), Baba et al.
patent: 4471646 (1984-09-01), Jerman et al.
patent: 4474889 (1984-10-01), Terry et al.
Terry, S. C. et al., "A Column Gas Chromatography System on a Single Wafer of Silicon" Des. Biomedical Appl. Solid State Chem. Sens. Workshop 1977.
Malir, K. et al., "Mass Flow Meter" IBM Technical Disclosure Bulletin, vol. 21, No. 8, Jan. 1979.
Svoboda, V. et al., "A Conductimetric Detector with a Wide Range for Liquid Chromotography" Journal of Chrom. 148 (1978) pp. 111-116.
Pecsok, R. et al., "A Sensitive Low Volume Detector for Liquid Chromatogrpahy" Analytical Chemistry, vol. 40, No. 11, Sep. 1968.
Foret, F. et al., "On-Line Fiber Optic UV Detection Cell and Conductivity Cell for Capillary Zone Electrophoresis" Electrophoresis 1986, 7, pp. 430-432.
Brettle Jack
Lowe Christopher
Sethi Rajinder S.
Niebling John F.
Starsiak Jr. John S.
LandOfFree
Chromatographic separation device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Chromatographic separation device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chromatographic separation device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1382127