US5880360A
Expired / Lapsed
US
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Method for imaging liquid and dielectric materials with scanning polarization force microscopy
Assignee: University of California Berkeley
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Filing: 1997-06-09
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Granted: 1999-03-09
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Expires: 2017-06-09
Abstract
Abstract The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.
Inventors
- 👤 Jun Hu
- 👤 D. Frank Ogletree
- 👤 Miguel Salmeron
- 👤 Xudong Xiao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:32
CPC Classifications
G; G01; G01Q; G01Q30/00; G01Q30/08; G01Q30/12; G01Q30/14; G01Q60/00; G01Q60/24; G01Q60/30; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/852; Y10S977/86
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
A method for using scanning force microscopy to image nonconducting materials using polarization force microscopy comprising the steps of: a) placing a nonconducting sample having a thickness greater than the radius of an electrically conducting scanning microscope probe tip between the tip and its counter electrode; b) applying a voltage to the probe tip relative to the counter electrode; c) moving the probe tip to the sample surface until a deflection of the probe tip is detected; d) scanning the surface of the sample with the probe tip; e) measuring an electrical signal arising at the probe tip as it scans the sample surface; and f) converting the electrical signal arising at the probe tip to an image.
Claim 2
Independent Claim
118 words
A method for using scanning force microscopy to image nonconducting materials using polarization force microscopy comprising the steps of: a) placing a nonconducting sample having a thickness greater than the radius of an electrically conducting scanning microscope probe tip between the tip and its counter electrode; b) applying a voltage to the probe tip relative to the counter electrode; c) moving the probe tip to the sample surface until a deflection of the probe tip is detected; d) scanning the surface of the sample with the probe tip; e) measuring an electrical signal arising at the probe tip as it scans the sample surface; and f) converting the electrical signal arising at the probe tip to an image.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the sample thickness is between about three times the probe tip radius and about 5 centimeters.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the sample thickness is between about nine times the probe tip radius and about 5 centimeters.
Claim 5
Dependent Claim
16 words
The method of claim 1 wherein the sample thickness is between 5,000 Å and 1,000,000,000 Å.
Claim 6
Dependent Claim
82 words
The method of claim 1 further comprising a constant-force method to image nonconducting materials using polarization forces further comprising the steps of: a) selecting the force level for scanning the sample; b) turning on an electrical feedback control system to maintain the probe tip-sample separation distance so that a constant force is maintained; and c) constructing a map of the variation in the distance between the probe tip and the sample that is required to maintain constant force on the probe tip.
Claim 7
Dependent Claim
99 words
The method of claim 1 further comprising a constant-distance method to image nonconducting materials using polarization forces comprising the steps of: a) obtaining an approach curve to determine the force as a function of distance between a scanning-microscope-probe-tip fulcrum and a sample; b) choosing a separation distance between the fulcrum and the sample with its corresponding force value; c) maintaining a constant distance between the fulcrum and the surface while scanning the surface; d) measuring the deflection of the cantilever portion of the probe tip during the scan; e) converting the deflection of the probe tip to an image.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-08 | 2002-09-07 | 2003-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-08 | 2006-09-07 | 2007-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-08 | 2010-09-07 | 2011-03-09 | $7700.00 | Window Closed / Lapsed |