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:
Mar. 23, 1999
Filed:
Oct. 04, 1996
Julia W Hsu, Charlottesville, VA (US);
Mark Lee, Charlottesville, VA (US);
Bascom S Dearer, Jr, Charlottesville, VA (US);
UVA Patent Foundation, Charlottesville, VA (US);
Abstract
A convenient, non-optical method for scanning probe microscopy tip-to-sample distance control based on the impedance change in a shear-force dither piezo. This is accomplished by determining the tip-sample distance by measuring the impedance change in a shear-force piezo-member. A Wheatstone type bridge can be utilized to regulate the tip-sample separation. Alternatively, an electrical bridge, having an output, regulates the tip-sample separation relative to the bridge output by driving the piezo/tip with a sine wave and combining said sine wave with a phase-referenced wave of equal amplitude at a 180.degree. phase shift. The electronic bridge detects impedance changes of about -100 dB across loads with impedance phases between -90.degree. to +90. Power dissipation is determined by measuring changes in electric impedance that a dither piezo presents to an oscillator. The non-optical method of determining probe-to-sample distance of an oscillating scanning probe consists of changing the probe-to-sample distance of an oscillating scanning probe. The changes in the electro-mechanical power dissipation of the oscillating probe are then measured.