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Micromechanical potentiometric sensors

United States Patent

6,016,686
January 25, 2000
View the Complete Patent at the US Patent & Trademark Office
Oak Ridge National Laboratory - Visit the Partnerships Directorate Website
A microcantilever potentiometric sensor utilized for detecting and measuring physical and chemical parameters in a sample of media is described. The microcantilevered spring element includes at least one chemical coating on a coated region, that accumulates a surface charge in response to hydrogen ions, redox potential, or ion concentrations in a sample of the media being monitored. The accumulation of surface charge on one surface of the microcantilever, with a differing surface charge on an opposing surface, creates a mechanical stress and a deflection of the spring element. One of a multitude of deflection detection methods may include the use of a laser light source focused on the microcantilever, with a photo-sensitive detector receiving reflected laser impulses. The microcantilevered spring element is approximately 1 to 100 .mu.m long, approximately 1 to 50 .mu.m wide, and approximately 0.3 to 3.0 .mu.m thick. An accuracy of detection of deflections of the cantilever is provided in the range of 0.01 nanometers of deflection. The microcantilever apparatus and a method of detection of parameters require only microliters of a sample to be placed on, or near the spring element surface. The method is extremely sensitive to the detection of the parameters to be measured.
Thundat; Thomas G. (Knoxville, TN)
Lockheed Martin Energy Research Corporation (Oak Ridge, TN)
09/ 042,601
March 16, 1998
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT The United States Government has certain rights in this invention pursuant to contracts numbers DE-AC05-96OR22464 and DE-AC05-84OR21400, between the U.S. Department of Energy and Lockheed Martin Energy Research Corporation.