US5212988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plate-mode ultrasonic structure including a gel
Assignee: University of California
•
Filing: 1991-10-10
•
Granted: 1993-05-25
•
Expires: 2011-10-10
Abstract
Abstract An ultrasonic structure which has a thin planar sheet of material forming a Lamb wave propagation medium The propagation medium is coated with a gel. The structure may also include a Lamb wave generator for generating Lamb waves in the propagation medium and an output device for producing an electrical signal representative of the propagation characteristics of the Lamb waves propagating along the propagation medium. A measuring device can be included to measure selected characteristics of the output electrical signal. The propagation medium has some physical characteristics that are determined by the value of a measurand acting on the medium and the determined physical characteristics determine the propagation characteristics of the Lamb waves which are propagated along the medium. When the sensor is acted on by a measurand to determine the physical characteristics of the propagation medium, the characteristics of the electrical signal are also determined. The measuring device measures the electrical signal and provides an indication of the measurand value.
Inventors
- 👤 Richard M. White
- 👤 Stuart W. Wenzel
- 👤 Benedict J. Costello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:18
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/22; G01N29/24; G01N29/2437; B; B01; B01L; B01L3/00; B01L3/50; B01L3/502; B01L3/5027; G01H; G01H13/00; G01H17/00; G01L; G01L9/00; G01L9/0001; G01L9/0008; G01L9/0022; G01L9/0025; G01N29/02; G01N29/022; G01P; G01P15/00; G01P15/02; G01P15/08; G10; G10K; G10K11/00; G10K11/36; H; H03; H03H; H03H9/00; H03H9/30; H03H9/42; B01L2300/00; B01L2300/06; B01L2300/0627; B01L2300/0663; B01L2300/18; B01L2300/1805; B01L2300/1827; B01L2400/00; B01L2400/04; B01L2400/0403; B01L2400/0415; B01L2400/0421; G01N2291/00; G01N2291/01; G01N2291/014; G01N2291/02; G01N2291/025; G01N2291/0255; G01N2291/0256; G01N2291/028; G01N2291/02818; G01N2291/02827; G01N2291/02854; G01N2291/04; G01N2291/042; G01N2291/0427
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
73 words
An ultrasonic structure comprising: a propagation medium comprising a thin planar sheet capable of supporting Lamb waves, said sheet having a thickness very much thinner than the wavelength of the Lamb waves to be propagated thereon, said propagation medium including on a surface thereof a layer of a low shear modulus material; and electrical means coupled to the thin planar sheet of said propagation medium for producing Lamb waves in the propagation medium.
Claim 2
Dependent Claim
73 words
An ultrasonic structure comprising: a propagation medium comprising a thin planar sheet capable of supporting Lamb waves, said sheet having a thickness very much thinner than the wavelength of the Lamb waves to be propagated thereon, said propagation medium including on a surface thereof a layer of a low shear modulus material; and electrical means coupled to the thin planar sheet of said propagation medium for producing Lamb waves in the propagation medium.
Claim 3
Dependent Claim
25 words
The structure as recited in claim 1, wherein the electrical means includes means for producing both symmetrical and antisymmetrical Lamb waves in the propagation medium.
Claim 4
Dependent Claim
17 words
The structure as recited in claim 2, wherein the propagation medium includes a layer of silicon nitride.
Claim 5
Dependent Claim
17 words
The structure as recited in claim 3, wherein the propagation medium includes a layer of piezoelectric material.
Claim 6
Dependent Claim
116 words
The structure as recited in claim 1 wherein said sheet has some physical characteristics determined by the value of a measurand acting thereon, said physical characteristics determining the propagation characteristics of Lamb waves to be propagated along the medium; and further including output means on said sheet for producing an electrical signal representative of the determined propagation characteristics of the Lamb waves propagating along the propagation medium, and measuring means for measuring selected characteristics of said electrical signal, whereby when said structure is acted on by a measurand, the physical characteristics of said propagation medium are determined and said electrical signal characteristics are also determined, so that said measuring means indicates the value of the measurand.
Claim 7
Dependent Claim
128 words
The structure as recited in claim 5, wherein the output means includes a receiving transducer, coupled to the propagation medium, for producing an electrical signal representative of the Lamb waves propagating along said propagation medium; the electrical means includes a launching transducer, coupled to the propagation medium, for generating Lamb waves in the propagation medium; a feedback path between the receiving and launching transducers for providing feedback from the receiving transducer to the launching transducer; a feedback amplifier in the feedback path for amplifying said electrical signal produced by the receiving transducer and fed back to the launching transducer, the structure forming an oscillator in which Lamb waves are continuously propagated along the propagation medium; and the measuring means includes frequency measuring means for measuring the oscillation frequency.
Claim 8
Dependent Claim
45 words
The structure as recited in claim 6, including Lamb wave reflecting means for reflecting Lamb waves generated by the launching transducer that propagate in directions away from the receiving transducer, so that the reflected Lamb waves do not produce an output at the receiving transducer.
Claim 9
Dependent Claim
18 words
The structure as recited in claim 1 wherein at least a portion of the propagation medium is porous.
Claim 10
Dependent Claim
18 words
The structure as recited in claim 8 wherein the porous portion of the propagation medium is also permeable.
Claim 11
Dependent Claim
27 words
The structure as recited in claim 1 wherein a layer of sorptive material is disposed between said propagation medium and said layer of low shear modulus material.
Claim 12
Dependent Claim
21 words
The structure as recited in claim 1 wherein a sorptive material is dispersed throughout said layer of low shear modulus material.
Claim 13
Dependent Claim
45 words
The structure as recited in claim 1 wherein said layer of low shear modulus material is a material selected from the group consisting of agar, gelatin, polyacrylamide, polyvinylalcohol, alginate, and other gels formed from seaweed, siloxanes, polyvinyl chloride gels, pectin, and the glycoprotein-based gel, mucus.
Claim 14
Dependent Claim
23 words
The structure as recited in claim 1 wherein the propagation medium includes a means of heating said layer of low shear modulus material.
Claim 15
Dependent Claim
20 words
The structure as recited in claim 1 wherein said layer of low shear modulus material contains cells or living organisms.
Claim 16
Dependent Claim
23 words
The structure as recited in claim 1 wherein said layer of low shear modulus material is bounded by a solid backing or support.
Claim 17
Dependent Claim
18 words
The structure as recited in claim 1 wherein both surfaces are coated with a layer of a gel.
Claim 18
Dependent Claim
16 words
The structure as recited in claim 1 wherein the electrical means for producing waves is electrostrictive.
Claim 19
Dependent Claim
16 words
The structure as recited in claim 1 wherein the electrical means for producing waves is thermoelastic.
Claim 20
Dependent Claim
16 words
The structure as recited in claim 1, including Lamb-wave reflecting means to form a Lamb-wave resonator.
Claim 21
Dependent Claim
197 words
An ultrasonic sensor comprising: a composite structure comprising (a) a supporting frame of a first material, and (b) a propagation medium comprising a thin planar sheet of a second different material capable of supporting Lamb waves, supported peripherally by said supporting frame, said sheet having a thickness very much thinner than the wavelength of Lamb waves to be propagated thereon and having some physical characteristics determined by the value of a measurand acting thereon, said physical characteristics determining the propagation characteristics of Lamb waves to be propagated along the medium, said propagation medium including on a surface thereof a layer of a gel; electrical means coupled to the thin planar sheet of said propagation medium for producing Lamb waves in the propagation medium; output means on said sheet for producing an electrical signal representative of the determined propagation characteristics of the Lamb waves propagating along the propagation medium; and measuring means for measuring selected characteristics of said electrical signal, whereby when said sensor is acted on by a measurand, the physical characteristics of said propagation medium are determined and said electrical signal characteristics are also determined, so that said measuring means indicates the value of the measurand.
Claim 22
Dependent Claim
197 words
An ultrasonic sensor comprising: a composite structure comprising (a) a supporting frame of a first material, and (b) a propagation medium comprising a thin planar sheet of a second different material capable of supporting Lamb waves, supported peripherally by said supporting frame, said sheet having a thickness very much thinner than the wavelength of Lamb waves to be propagated thereon and having some physical characteristics determined by the value of a measurand acting thereon, said physical characteristics determining the propagation characteristics of Lamb waves to be propagated along the medium, said propagation medium including on a surface thereof a layer of a gel; electrical means coupled to the thin planar sheet of said propagation medium for producing Lamb waves in the propagation medium; output means on said sheet for producing an electrical signal representative of the determined propagation characteristics of the Lamb waves propagating along the propagation medium; and measuring means for measuring selected characteristics of said electrical signal, whereby when said sensor is acted on by a measurand, the physical characteristics of said propagation medium are determined and said electrical signal characteristics are also determined, so that said measuring means indicates the value of the measurand.
Claim 23
Dependent Claim
21 words
The sensor as recited in claim 20, wherein there is a ground plane that is substantially coextensive with the propagation medium.
Claim 24
Dependent Claim
18 words
The sensor as recited in claim 20, wherein at least a portion of the propagation medium is porous.
Claim 25
Dependent Claim
18 words
The sensor as recited in claim 22, wherein the porous portion of the propagation medium is also permeable.
Claim 26
Dependent Claim
23 words
The sensor as recited in claim 20, wherein a layer of sorptive material is disposed between said propagation medium and said gel layer.
Claim 27
Dependent Claim
17 words
The sensor as recited in claim 20, wherein a sorptive material is dispersed throughout said gel layer.
Claim 28
Dependent Claim
22 words
The sensor as recited in claim 20 further including a layer of protective material as an outer surface on said gel layer.
Claim 29
Dependent Claim
23 words
The sensor as recited in claim 26, wherein said protective layer is a material selected from the group consisting of Teflon and silicone.
Claim 30
Dependent Claim
41 words
The sensor as recited in claim 20, wherein said gel layer is a material selected from the group consisting of agar, gelatin, polyacrylamide, polyvinylalcohol, alginate, and other gels formed from seaweed, siloxanes, polyvinyl chloride gels, pectin, and the glycoprotein-based gel, mucus.
Claim 31
Dependent Claim
19 words
The sensor as recited in claim 20, wherein the propagation medium includes a means of heating said gel layer.
Claim 32
Dependent Claim
16 words
The sensor as recited in claim 20, wherein said gel layer contains cells or living organisms.
Claim 33
Dependent Claim
19 words
The sensor as recited in claim 20, wherein said gel layer is bounded by a solid backing or support.
Claim 34
Dependent Claim
22 words
The sensor as recited in claim 20, wherein both surfaces of the propagation medium are coated with a layer of a gel.
Claim 35
Dependent Claim
16 words
The sensor as recited in claim 20 wherein the electrical means for producing waves is electrostrictive.
Claim 36
Dependent Claim
16 words
The sensor as recited in claim 20 wherein the electrical means for producing waves is thermoelastic.
Claim 37
Dependent Claim
25 words
The sensor as recited in claim 20, wherein the electrical means includes means for producing both symmetrical and antisymmetrical Lamb waves in the propagation medium.
Claim 38
Dependent Claim
17 words
The sensor as recited in claim 35, wherein the propagation medium includes a layer of silicon nitride.
Claim 39
Dependent Claim
17 words
The sensor as recited in claim 36, wherein the propagation medium includes a layer of piezoelectric material.
Claim 40
Dependent Claim
128 words
The sensor as recited in claim 38, wherein the output means includes a receiving transducer, coupled to the propagation medium, for producing an electrical signal representative of the Lamb waves propagating along said propagation medium, the electrical means includes a launching transducer, coupled to the propagation medium, for generating Lamb waves in the propagation medium, a feedback path between the receiving and launching transducers for providing feedback from the receiving transducer to the launching transducer, and a feedback amplifier in the feedback path for amplifying said electrical signal produced by the receiving transducer and fed back to the launching transducer, the sensor forming an oscillator in which Lamb waves are continuously propagated along the propagation medium, the measuring means includes frequency measuring means for measuring the oscillation frequency.
Claim 41
Dependent Claim
45 words
The sensor as recited in claim 38, including Lamb wave reflecting means for reflecting Lamb waves generated by the launching transducer that propagate in directions away from the receiving transducer, so that the reflected Lamb waves do not produce an output at the receiving transducer.
Claim 42
Dependent Claim
27 words
The sensor as recited in claim 38, wherein each transducer includes a pair of interdigital finger electrodes formed on one surface of the layer of piezoelectric material.
Claim 43
Dependent Claim
50 words
The sensor as recited in claim 40, wherein the propagation medium includes a ground plane comprising a layer of conducting material on the surface of the piezoelectric layer opposite the surface on which the transducer electrodes are deposited, said ground plane being restricted to areas substantially opposite the transducer electrodes.
Claim 44
Dependent Claim
66 words
An ultrasonic structure comprising: a propagation medium comprising a thin planar sheet capable of supporting Lamb waves, said sheet having a thickness very much thinner than the wavelength of the Lamb waves to be propagated thereon, said propagation medium including on a surface thereof a layer of a low shear modulus material; and optical means for the thermoelastic generation of Lamb waves in the propagation medium.
Claim 45
Dependent Claim
66 words
An ultrasonic structure comprising: a propagation medium comprising a thin planar sheet capable of supporting Lamb waves, said sheet having a thickness very much thinner than the wavelength of the Lamb waves to be propagated thereon, said propagation medium including on a surface thereof a layer of a low shear modulus material; and optical means for the thermoelastic generation of Lamb waves in the propagation medium.
References Cited (Backward Citations)
GB1330142A
Cited
US3786373A
Cited
US3878477A
Cited
US3965444A
Cited
US4361026A
Cited
US4404852A
Cited
US4480209A
Cited
US4463336A
Cited
US4456850A
Cited
SU1191817A1
Cited
US4623813A
Cited
US4598224A
Cited
US4672354A
Cited
US4670092A
Cited
US4805456A
Cited
US5129262A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-24 | 1996-11-23 | 1997-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-24 | 2000-11-23 | 2001-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-24 | 2004-11-23 | 2005-05-25 | $7700.00 | Window Closed / Lapsed |