Composite autoclavable ultrasonic transducers and methods of making
First Claim
1. A transducer for emitting and detecting ultrasonic energy, comprising:
- at least one row of individually-addressable transducer elements, extending in a first dimension;
each element comprising a plurality of piezoelectric emitters arranged in at least one row extending in a second dimension perpendicular to said first dimension, said emitters being spaced from one another by a polymer matrix;
each emitter comprising a plurality of individual ceramic members stacked in a third dimension perpendicular to said first and second dimensions, said individual ceramic members being connected to parallel elongated strip-like conductors disposed between the individual ceramic members of each emitter and extending parallel to the second dimension to reach opposed edges of said array;
adjacent ones of said elements and said emitters being separated from one another solely by continuous planar members of a polymer matrix extending perpendicular to said first dimension, said elongated strip-like conductors extending between said planar members; and
external connection means connected to said conductors at said opposed edges of said array, electrical connection between said external connection means and upper and lower surfaces of said individual ceramic members being provided solely by said strip-like conductors, and whereby each of the individual ceramic members of each of the emitters of each element may be excited simultaneously by electrical drive signals in order to collectively emit ultrasonic energy.
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Accused Products
Abstract
An improved composite ultrasonic transducer, and elements therefor, which may be made autoclavable, and a method of making these elements. A number of planar precursors comprising strips of piezoelectric ceramic material separated from one another by a polymer material are stacked one above another with the ceramic strips aligned with one another, and with electrical conductors disposed between each of the planar precursors. These precursors are then bonded to one another, to form a bonded assembly. The bonded assembly is then slit along parallel lines perpendicular to the direction of elongation of the ceramic strips, subdividing the strips into individual ceramic members and also subdividing the planar conductors, forming ribbon-like conductors extending between opposite sides of the array. The saw kerfs are filled with a hardening polymer material. The ribbon-like conductors reaching the edges of the assembly are then connected electrically in parallel, reducing the capacitance of the individual emitters. Criteria for selection of the materials of the ceramic members, the conductors, and other components of the transducer, and their relative proportions are given which allow the transducer to be steam-autoclavable.
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Citations
18 Claims
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1. A transducer for emitting and detecting ultrasonic energy, comprising:
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at least one row of individually-addressable transducer elements, extending in a first dimension; each element comprising a plurality of piezoelectric emitters arranged in at least one row extending in a second dimension perpendicular to said first dimension, said emitters being spaced from one another by a polymer matrix; each emitter comprising a plurality of individual ceramic members stacked in a third dimension perpendicular to said first and second dimensions, said individual ceramic members being connected to parallel elongated strip-like conductors disposed between the individual ceramic members of each emitter and extending parallel to the second dimension to reach opposed edges of said array; adjacent ones of said elements and said emitters being separated from one another solely by continuous planar members of a polymer matrix extending perpendicular to said first dimension, said elongated strip-like conductors extending between said planar members; and external connection means connected to said conductors at said opposed edges of said array, electrical connection between said external connection means and upper and lower surfaces of said individual ceramic members being provided solely by said strip-like conductors, and whereby each of the individual ceramic members of each of the emitters of each element may be excited simultaneously by electrical drive signals in order to collectively emit ultrasonic energy. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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- 8. An element for an ultrasonic transducer, wherein a plurality of said elements may be arranged in a row extending in a first dimension with a polymer layer between adjacent elements to form a tranducer, said element comprising an array of individual piezoelectric emitters spaced from one another in at least a second dimension by a polymer matrix, each emitter comprising a number of individual ceramic members stacked upon one another in a third dimension, juxtaposed individual ceramic members of each emitter being connected to one another by being bonded on opposite faces of strip-like electrical conductors extending continuously between opposed edges of said array in said second dimension, such that each of said members of said element can be excited simultaneously by a drive signal applied to said conductors by connections made at the edges of said array.
- 13. A steam-autoclavable ultrasonic transducer comprising a number of elements arranged in a row extending in a first dimension, and each element comprising at least two composite layers each including a plurality of individual ceramic members spaced from one another in at least a second dimension by a polymer matrix, strip-like front and rear conductors extending substantially continuously across said composite layers from one side to the other in the direction of said second dimension and electrically connected to front and rear surfaces of said individual members, adjacent ones of said elements and said conductors being separated from one another in said first dimension solely by planar polymer members extending transverse to said first dimension, wherein said ceramic members are formed from a piezoelectric ceramic material which does not lose its piezoelectric property when exposed to autoclaving temperatures, the material of said polymer matrix is epoxy and/or silicone rubber, and the material of said conductors is one or more of gold, silver, chromium, copper, or nickel.
Specification