The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 10, 1992
Filed:
Jan. 22, 1991
Elio A Mariani, Hamilton Square, NJ (US);
Raymond McGowan, Neptune, NJ (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A method and apparatus directed to a thin film piezoelectric resonator deposited on a support layer of dielectric material and being configured in the form of a cantilever structure having a base portion formed on an integrated circuit substrate and having an overhanging beam portion joined at one end to the base portion, with the opposite end being unsupported with an air-gap intermediate the beam portion and the substrate. In the fabrication of the resonator, a thin film of dielectric material, e.g. zinc oxide (ZnO) is first deposited on the substrate, but is subsequently removed from beneath the beam portion resulting in the air-gap which is open on three sides and thus results in a greater ease of fabrication. A completely monolithic chemical detector is implemented utilizing a matched pair of these cantilevered air-gap thin film resonators, with one of the resonators further including a coating on one of its electrodes and which is responsive to a predetermined chemical to cause a frequency shift in the presence of the chemical to be detected. In one embodiment of the chemical detector, the frequency outputs of the two resonators are compared with the difference frequency providing an indication of the chemical being detected.