Patent Number: 6,167,748

Title: Capacitively readout multi-element sensor array with common-mode cancellation

Abstract: An improved multi-element apparatus for detecting the presence of at least one chemical, biological or physical component in a monitored area comprising an array or single set of the following elements: a capacitive transducer having at least one cantilever spring element secured thereto, the cantilever element having an area thereof coated with a chemical having an affinity for the component to be detected; a pick-up plate positioned adjacent to the cantilever element at a distance such that a capacitance between the cantilever element and the pick-up plate changes as the distance between the cantilever element and the pick-up plate varies, the change in capacitance being a measurable variation; a detection means for measuring the measurable variation in the capacitance between the cantilever element and the pick-up plate that forms a measurement channel signal; and at least one feedback cantilever spring element positioned apart from the coated cantilever element, the cantilever element substantially unaffected by the component being monitored and providing a reference channel signal to the detection means that achieves a common mode cancellation between the measurement channel signal and reference channel signal.

Inventors: Britton, Jr.; Charles L. (Alcoa, TN), Warmack; Robert J. (Knoxville, TN), Bryan; William L. (Knoxville, TN), Jones; Robert L. (Decatur, TN), Oden; Patrick Ian (Knoxville, TN), Thundat; Thomas (Knoxville, TN)

Assignee: Lockheed Martin Energy Research Corporation

International Classification: G01B 7/16 (20060101); G01N 27/00 (20060101); G01N 27/22 (20060101); G01N 19/10 (20060101); G01M 3/04 (20060101); G01N 27/24 (20060101); G01B 7/34 (20060101); G01D 5/12 (20060101); G01N 19/00 (20060101); G01D 5/241 (20060101); G01N 33/543 (20060101); G01B 007/16 (); G01M 003/04 (); G01N 019/10 (); G01N 027/00 (); G01N 033/543 ()

Expiration Date: 01/02/2018