Piezeoelectric transducer having protuberances for transmitting acoustic energy and method of making the same
First Claim
1. An ultrasonic transducer apparatus comprising:
- a substrate having an array of apertures respectively formed therein at predetermined positions on the substrate such that the array forms a given area within the substrate;
a layer of polymeric piezoelectric material disposed on the substrate, the layer of piezoelectric material having a plurality of protuberances each being defined by a respective portion of the piezoelectric material extending into a corresponding one the apertures, the plurality of protuberances being substantially permanently formed and defining an active area of the transducer corresponding to the given area of the substrate;
wherein a resonance frequency of the transducer is a function of a shape of the protuberances as determined by at least one dimension of the apertures, and wherein a vertical and horizontal beam angle associated with the transducer is controllable as a function of the dimensions of the active area of the transducer.
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Accused Products
Abstract
A method of forming an ultrasound transducer having thermoformed protuberances comprises providing a substrate having a plurality of perforations of a given dimension. The perforations or apertures are formed in the substrate and operate to determine the resonance frequency associated with the transducer. A film of polymeric material capable of showing piezoelectric properties when strained in its plane and electrically biassed by a field applied in a direction normal to its faces, is then laminated onto the substrate. The film is heated to a given temperature and a pressure differential is applied between the top and bottom surfaces of the film for a sufficient time to form protuberances in the film through the apertures in the substrate. The film is then cooled to a given ambient temperature while maintaining a pressure differential between the top and bottom surfaces of the film for a sufficient time until the ambient temperature is reached so as to cause the protuberances to maintain a substantially permanent curvature.
66 Citations
18 Claims
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1. An ultrasonic transducer apparatus comprising:
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a substrate having an array of apertures respectively formed therein at predetermined positions on the substrate such that the array forms a given area within the substrate;
a layer of polymeric piezoelectric material disposed on the substrate, the layer of piezoelectric material having a plurality of protuberances each being defined by a respective portion of the piezoelectric material extending into a corresponding one the apertures, the plurality of protuberances being substantially permanently formed and defining an active area of the transducer corresponding to the given area of the substrate;
wherein a resonance frequency of the transducer is a function of a shape of the protuberances as determined by at least one dimension of the apertures, and wherein a vertical and horizontal beam angle associated with the transducer is controllable as a function of the dimensions of the active area of the transducer.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A flat ultrasonic transducer comprising:
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a flat substrate having a plurality of apertures formed therein;
a layer of polymeric piezoelectric material disposed on the flat substrate, the layer of piezoelectric material including a plurality of protuberances defined by portions of the piezoelectric material extending into corresponding ones of the apertures, the plurality of protuberances defining an active area of the transducer;
wherein the resonance frequency of the transducer is a function of a curvature of each of the protuberances as determined by at least one dimension of the apertures, and wherein the output power is controllable as a function of the ratio of the active area to the total substrate area.
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14. A transducer comprising:
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a curved substrate having a plurality of apertures formed therein;
a layer of polymeric piezoelectric material disposed along the curved substrate, the layer of piezoelectric material including a-plurality of protuberances of a given curvature, the protuberances each being defined by portions of the piezoelectric material extending into a corresponding one of the apertures, the plurality of protuberances defining an active area of the transducer;
contact means coupled to the piezoelectric material for providing an electrical input to cause vibration of said protuberances at a predetermined frequency which is independent of the radius of curvature of the curved substrate. - View Dependent Claims (15, 16)
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17. An ultrasonic transducer assembly comprising:
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an ultrasound transducer including;
a substrate including top and bottom surfaces, the substrate formed of a conductive material and including a plurality of apertures formed therethrough;
a laminate comprising a film of a polymer piezoelectric material sandwiched between a first electrode layer on a top surface and a second electrode layer on a bottom surface, the laminate disposed on the top surface of the substrate, the laminate including a plurality of protuberances each of a given curvature and respectively extending into a corresponding one the apertures; and
a housing containing the ultrasound transducer, the housing including an open end and a closed end, the housing comprising;
a first contact in electrical communication with the first electrode layer;
a second contact in electrical communication with the second electrode layer;
means coupled to the first contact for providing a first electrical connection through the closed end to provide a first terminal for connection to a first electrical potential; and
,means coupled to the second contact for providing a second electrical connection through the closed end to provide a second terminal for connection to a second electrical potential;
whereby the substrate is operative to provide mechanical protection to the transducer laminate and to electrically couple the first and second electrode layers each to a corresponding terminal.
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18. A housing assembly for an ultrasound transducer comprising a substrate including top and bottom surfaces, the substrate formed of a conductive material and including a plurality of apertures formed therethrough;
- a laminate comprising a film of polymer piezoelectric material sandwiched between a first electrode layer on a top surface and a second electrode layer on a bottom surface, the laminate disposed on the top surface of the substrate, the laminate including a plurality of protuberances each of a given curvature and extending into a corresponding one of the apertures;
the housing assembly comprising;a first contact in electrical communication with the first electrode, the first contact having a first arm member;
a second contact in electrical communication with the substrate and having a second arm member;
an end cap member having a first slot for receiving the first arm member to provide a first terminal, and a second slot for receiving the second arm member to provide a second terminal, the first and second terminal operable to provide external connectivity thereto;
a front member disposed opposite the end cap member; and
means for securing the front member to the end cap member for retaining the transducer within the housing.
- a laminate comprising a film of polymer piezoelectric material sandwiched between a first electrode layer on a top surface and a second electrode layer on a bottom surface, the laminate disposed on the top surface of the substrate, the laminate including a plurality of protuberances each of a given curvature and extending into a corresponding one of the apertures;
Specification