Measuring and testing – Gas analysis – By vibration
Utility Patent
1998-08-31
2001-01-02
Williams, Hezron (Department: 2856)
Measuring and testing
Gas analysis
By vibration
C073S024010, C073S778000, C073S061490, C073S061750, C435S006120, C435S007100, C436S501000, C436S806000, C436S151000, C422S088000, C422S069000, C204S403060
Utility Patent
active
06167748
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to instruments for measuring the concentration of a chemical, physical or biological presence or component dispersed within a monitored area. Specifically, the invention relates to a microcantilever sensor which measures the concentration of a chemical, physical or biological presence or component dispersed within a monitored area.
BACKGROUND OF THE INVENTION
A pressing need exists in many industries, disciplines and governmental interests for a highly sensitive and selective detector of quantifying chemical, physical or biological presences or components in a monitored area. To qualify, such a detector must have such diverse characteristics as being small, rugged, inexpensive, selective, reversible and extremely sensitive. Applicants have invented other apparatuses directed to this pressing need in the industry. U.S. Pat. No. 5,719,324 to Thundat and U.S. Pat. No. 5,445,008 to Wachter, incorporated herein by reference and commonly assigned to Applicant, both describe such technology.
These prior art references disclose microcantilever sensor technology which is a next-generation electromechanical technique with broad application in chemical, physical and biological detection. Depending on the dimensions of the microcantilever platform and the cantilever spring constant, deflections of these cantilevers can be detected with sub-Angstrom precision using current techniques employed by atomic force microscopy (AMF) technology such as optical, piezoresistive, piezoelectric, capacitive, and electron tunneling. To date, however, available technology has limited the use of cantilevers to a single read out, normally by optical beams. This use is cumbersome and time consuming.
The present invention focuses on developing arrayable, electronically read cantilevers which are selectively coated with certain chemicals to achieve a sensitivity to a specific physical, chemical or biological presence, e.g., relative humidity, mercury vapor, mercaptan, toluene, viscosity infrared and ultraviolet radiation, flow rate, lead in water, DNA hybridization, and antibody-antigen interaction. The cantilevers of the present invention convert a change in capacitance into a signal which is ultimately converted into a DC voltage output for further processing.
In accordance with the present invention, an array of cantilevers with a variety of different coatings may be placed on a single chip in order to detect the presence of various chemical, physical or biological presences. As the coatings react with the presence or component sensed, the change in stress causes a deflection of the cantilever, thus, changing the space between the cantilever and an associated lower plate. This change is sensed as a change in capacitance.
Sensing electronics associated with the cantilever perform several novel functions. First, the sensing electronics are able to provide a simultaneous or sequential readout of all cantilevers in an array. Second, the sensing electronics utilize a virtual ground on both sides of the cantilever capacitance in order to minimize the effects of stray capacitance, thus, allowing the location of the readout amplifier away from the cantilever without effecting the signal gain. And, third, the sensing electronics utilizes a differential common-mode cancellation to remove from the data the effects of externally caused noises from sources such as power supply variations, preamplifier pickup, or vibration. The same differential operation could also be used to reduce errors caused by temperature, humidity and interfering chemical components.
OBJECTS OF THE INVENTION
It is, thus, an object of the present invention to provide an apparatus and method for measuring concentrations of a chemical, physical or biological presence, that may be present within a monitored area.
It is a further object of the present invention to provide an apparatus for measuring chemical, physical or biological presences, the apparatus being arrayable and electronically read.
It is another object of the present invention to provide an apparatus which is capable of simultaneous read out of arrays.
It is yet a further object of the present invention to provide an apparatus which is capable of providing an output signal reflective of the accumulation of a chemical, physical or biological presence sought to be detected.
It is yet another object of the present invention to provide an apparatus which is capable of providing an output signal free from the effects of stray capacitance and common-mode noises.
REFERENCES:
patent: Re. 35544 (1997-07-01), Snow
patent: 3828607 (1974-08-01), Janzen et al.
patent: 4236893 (1980-12-01), Rice
patent: 4242096 (1980-12-01), Oliveira et al.
patent: 4584885 (1986-04-01), Cadwell
patent: 4596697 (1986-06-01), Ballato
patent: 4637987 (1987-01-01), Minten et al.
patent: 4656871 (1987-04-01), Czarnocki
patent: 4735906 (1988-04-01), Bastiaans
patent: 4847193 (1989-07-01), Richards et al.
patent: 4905701 (1990-03-01), Cornelius
patent: 4906840 (1990-03-01), Zdeblick et al.
patent: 4999284 (1991-03-01), Ward et al.
patent: 5001053 (1991-03-01), Takahashi et al.
patent: 5130257 (1992-07-01), Baer et al.
patent: 5135852 (1992-08-01), Ebersole et al.
patent: 5156972 (1992-10-01), Issachar
patent: 5179028 (1993-01-01), Vali et al.
patent: 5221415 (1993-06-01), Albrecht et al.
patent: 5283037 (1994-02-01), Baer et al.
patent: 5306644 (1994-04-01), Myerholtz et al.
patent: 5323636 (1994-06-01), McGowan et al.
patent: 5339675 (1994-08-01), DiLeo et al.
patent: 5363697 (1994-11-01), Nakagawa
patent: 5372930 (1994-12-01), Colton et al.
patent: 5411709 (1995-05-01), Furuki et al.
patent: 5445008 (1995-08-01), Wachter et al.
patent: 5445970 (1995-08-01), Rohr
patent: 5445971 (1995-08-01), Rohr
patent: 5477716 (1995-12-01), Snow
patent: 5482678 (1996-01-01), Sittler
patent: 5494639 (1996-02-01), Grzegorzewski
patent: 5501986 (1996-03-01), Ward et al.
patent: 5552274 (1996-09-01), Oyama et al.
patent: 5595908 (1997-01-01), Fawcett et al.
patent: 5658732 (1997-08-01), Ebersole et al.
patent: 5705399 (1998-01-01), Larue
patent: 5719324 (1998-02-01), Thundat et al.
patent: 5763283 (1998-06-01), Cernosek et al.
patent: 5804709 (1998-09-01), Bourgoin et al.
patent: 5936150 (1999-08-01), Kobrin et al.
patent: 5959957 (1999-09-01), Ikeda et al.
patent: 6016686 (2000-01-01), Thundat
patent: WO 94 28372 (1994-12-01), None
MEMS Sensors and Wireless Telemetry for Distributed Systems —C. L. Britton et al., presented at the SPIE 5th International Symposium on Smart Materials and Structures, Mar. 2, 1998, San Diego, California.
Microfabrication of Cantilever Styli for the Atomic Force Microscope —T. R. Albrecht, 1990 American Vacuum Society, pp. 3386-3396, v.
Photothermal Spectroscopy with Femtojoule Sensitivity Using a Micromechanical Device —J. R. Barnes, et al., Nature, vol. 372-3 Nov. 1994, pp. 79-81.
A Mechanical Nanosensor in the Gigahertz Range: Where Mechanics Meets Electronics —Surface Science Letters—1994.
A Nondestructive Method for Determining the Spring Constant of Cantilevers for Scanning Force Microscopy —J. P. Cleveland et al., Science, vol. 64, No. 2, Feb. 1993.
Observation of a Chemical Reaction Using a Micromechanical Sensor —J. K. Gimzewski et al., Chemical Physics Letters, vol. 217, No. 5.6, pp. 589-594.
Measuring Intermolecular Binding Forces with the Atomic-Force Microscope: The Magnetic Jump Method —Hoh et al., Proceedings, Fifty-Second Annual Meeting Microscopy Society of America, Jul. 31-Sep. 5 1994, pp. 1054-1055.
Journal of the American Chemical Society—B. G. Rao et al., Jun. 3, 1992, vol. 114, No. 12.
Sensing Discrete Steptavidin-Biotin Interactions with Atomic Force Microscopy—Gil U. Lee, et al., Langmuir, vol. 10, No. 2, 1994.
A Novel Readout Technique for Capacitive Gas Sensors—Sensors and Actuators, B1 (1990), pp. 58-61, U. Schoeneberg, B. J. Hosticka, G. Zimmer and G. J. Maclay.
A Capactive Pressure Sensor With Low Impedance Output and Active Suppression of Parasite Effects,Sensors and Actuators, A21-A23 (1990), pp. 108-114, B. Puers, E Peeters, A
Britton, Jr. Charles L.
Bryan William L.
Jones Robert L.
Oden Patrick Ian
Thundat Thomas
Hardaway/Mann IPGroup
Lockheed Martin Energy Research Corporation
Nexsen Pruet Jacobs & Pollard LLP
Wiggins J. David
Williams Hezron
LandOfFree
Capacitively readout multi-element sensor array with... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Capacitively readout multi-element sensor array with..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capacitively readout multi-element sensor array with... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2487488