Patent US5287331A successfully refreshed from Google Patents.
US5287331A
Expired / Lapsed
US
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Air coupled ultrasonic transducer
Assignee: Parteq Innovations
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Filing: 1992-10-26
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Granted: 1994-02-15
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Expires: 2012-10-26
Abstract
Abstract An acoustic transducer which is operable in air up to at least 2MHz is described. A conducting substrate, usually a silicon wafer is etched to provide a selected pattern of micro pits up to about 30 μm or more deep. A dielectric film, such as a polyimide film is placed over the etched surface so as to trap air in each individual pit. A conducting upper layer is then superimposed over the dielectric film. When a potential is applied between the substrate and the upper layer the upper layer is driven into motion and enhanced by the vibrations of the air pockets. Alternatively a smooth substrate may be employed in conjunction with an etched dielectric film to achieve the same result. These transducers are useful for non-destructive testing of large structures or for medical diagnostic and therapeutic purposes, without the need for a liquid or gel coupling agent.
Inventors
- 👤 David W. Schindel
- 👤 David A. Hutchins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:07
CPC Classifications
H; H04; H04R; H04R17/00; H04R17/005; A; A61; A61B; A61B17/00; A61B17/22; A61B17/22004; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
87 words
An acoustic transducer operable in air up to at least 2 MH z , comprising: a substrate having at least one conducting surface and having a plurality of pits of selected size and shape distributed in a selected pattern over at least one surface thereof; at least one dielectric film superimposed over said pits in said one surface of said substrate so as to provide a plurality of air pockets between said substrate and said dielectric film; and a conducting upper electrode superimposed on said dielectric film.
Claim 2
Dependent Claim
87 words
An acoustic transducer operable in air up to at least 2 MH z , comprising: a substrate having at least one conducting surface and having a plurality of pits of selected size and shape distributed in a selected pattern over at least one surface thereof; at least one dielectric film superimposed over said pits in said one surface of said substrate so as to provide a plurality of air pockets between said substrate and said dielectric film; and a conducting upper electrode superimposed on said dielectric film.
Claim 3
Dependent Claim
21 words
An acoustic transducer as claimed in claim 1 including means to secure said dielectric film in superimposed relation on said substrate.
Claim 4
Dependent Claim
22 words
An acoustic transducer as claimed in claim 2 wherein said conducting upper electrode comprises a metallic film deposited on said dielectric film.
Claim 5
Dependent Claim
17 words
An acoustic transducer as claimed in claim 1 wherein said conducting substrate comprises a semi conducting material.
Claim 6
Dependent Claim
20 words
An acoustic transducer as claimed in claim 1 wherein said conducting substrate comprises a glass plate having a conducting surface.
Claim 7
Dependent Claim
18 words
An acoustic transducer as claimed in claim 1 wherein said substrate, dielectric film and upper electrode are planar.
Claim 8
Dependent Claim
17 words
An acoustic transducer as claimed in claim 4 wherein said semi conducting material is a silicon wafer.
Claim 9
Dependent Claim
19 words
An acoustic transducer as claimed in claim 5 wherein said pits in said substrate comprise chemically produced etch pits.
Claim 10
Dependent Claim
22 words
An acoustic transducer as claimed in claim 1 wherein said dielectric film is selected from an electric film and piezoelectric polymer film.
Claim 11
Dependent Claim
16 words
An acoustic transducer as claimed in claim 9 wherein said dielectric film is a polyimide film.
Claim 12
Dependent Claim
15 words
An acoustic transducer as claimed in claim 1 wherein said pits extend through said substrate.
Claim 13
Dependent Claim
18 words
An acoustic transducer as claimed in claim 3 wherein said metallic film is selected from gold and aluminum.
Claim 14
Dependent Claim
24 words
An acoustic transducer as claimed in claim 7 wherein said pits are hexagonal and have an average depth of up to about 30 μm.
Claim 15
Independent Claim
63 words
A method for producing an acoustic transducer operable in air up to at least 2 MHz, comprising: (a) producing a selected pattern of pits in a surface of a conducting substrate; (b) superimposing said pitted surface with a film of dielectric material so as to trap air into a plurality of said pits; and (c) superimposing a conducting electrode over said dielectric film.
Claim 16
Independent Claim
63 words
A method for producing an acoustic transducer operable in air up to at least 2 MHz, comprising: (a) producing a selected pattern of pits in a surface of a conducting substrate; (b) superimposing said pitted surface with a film of dielectric material so as to trap air into a plurality of said pits; and (c) superimposing a conducting electrode over said dielectric film.
Claim 17
Dependent Claim
22 words
A method as claimed in claim 14, wherein said pits are produced by chemical etching, ion beam milling or reactive ion etching.
Claim 18
Dependent Claim
22 words
A method as claimed in claim 14 wherein said conducting substrate is a semi conductor material selected from silicon and doped silicon.
Claim 19
Dependent Claim
16 words
A method as claimed in claim 16 wherein said pits are up to 30 μm deep.
Claim 20
Dependent Claim
28 words
A method as claimed in claim 14 including the step of spin coating a polyimide material on said substrate so as to form said film of dielectric material.
Claim 21
Dependent Claim
13 words
A method as claimed in claim 18 wherein said polyimide is Probimide 200.
Claim 22
Dependent Claim
21 words
A method as claimed in claim 14 wherein said planar conducting electrode comprises a metallic layer selected from aluminum and gold.
Claim 23
Dependent Claim
17 words
A method as claimed in claim 20 wherein said metallic layer is applied by vapour phase deposition.
Claim 24
Dependent Claim
69 words
An acoustic transducer operable in air up to at least 2 MHz, comprising a substrate having at least one conducting surface; at least one dielectric film having a plurality of pits of selected size and shape distributed thereover in a selected pattern, superimposed over said substrate so as to provide a plurality of air pockets between said dielectric film; and a conducting upper electrode superimposed on said dielectric film.
Claim 25
Dependent Claim
69 words
An acoustic transducer operable in air up to at least 2 MHz, comprising a substrate having at least one conducting surface; at least one dielectric film having a plurality of pits of selected size and shape distributed thereover in a selected pattern, superimposed over said substrate so as to provide a plurality of air pockets between said dielectric film; and a conducting upper electrode superimposed on said dielectric film.
Claim 26
Dependent Claim
16 words
An acoustic transducer as claimed in claim 22 wherein said pits extend through said dielectric film.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-02-14 | 1997-08-16 | 1998-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-14 | 2001-08-16 | 2002-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-14 | 2005-08-16 | 2006-02-15 | $7700.00 | Window Closed / Lapsed |