High frequency ultrasonic transducer and matching layer comprising cyanoacrylate
In one aspect, matching layers for an ultrasonic transducer stack having a matching layer comprising a matrix material loaded with a plurality of micron-sized and nano-sized particles. In another aspect, the matrix material is loaded with a plurality of heavy and light particles. In another aspect, an ultrasound transducer stack comprises a piezoelectric layer and at least one matching layer. In one aspect, the matching layer comprises a composite material comprising a matrix material loaded with a plurality of micron-sized and nano-sized particles. In a further aspect, the composite material can also comprise a matrix material loaded with a plurality of heavy and light particles. In a further aspect, a matching layer can also comprise cyanoacrylate.
1. An ultrasonic transducer stack, comprising:
a plurality of layers comprising:
a piezoelectric layer configured to operate at a center frequency of 20 MHz or greater;
at least one matching layer that comprises a first a matching layer comprising cyanoacrylate; and
a lens layer comprising TPX, wherein each layer of the plurality of layers has a top surface and an opposed bottom surface, wherein the matching layer is connected to and underlies the bottom surface of the lens layer, and wherein the piezoelectric layer underlies the bottom surface of the matching layer.
2. The ultrasonic transducer stack of claim 1 , wherein the matching layer is about a ¼ acoustic wavelength matching layer.
3. The ultrasonic transducer stack of claim 2 , wherein the acoustic impedance of the matching layer is between about 2.0 MegaRayles (MR) to about 3.5 MegaRayles (MR).
4. The ultrasonic transducer stack of claim 2 , wherein the acoustic impedance of the matching layer is between about 2.5 MegaRayles (MR) to about 2.8 MegaRayles (MR).
5. The ultrasonic transducer stack of claim 2 , wherein the acoustic impedance of the lens layer is about 1.8 MegaRayles (MR).
6. The ultrasonic transducer stack of claim 1 , wherein the acoustic impedance of the lens is substantially the same as the acoustic impedance of water.
7. The ultrasonic transducer stack of claim 1 , wherein the matching layer is a first matching layer, further comprising a second matching layer located between the top surface of the piezoelectric layer and the bottom surface of the first matching layer.
8. The ultrasonic transducer stack of claim 7 , wherein the top surface of the second matching layer is bonded to the bottom surface of the first matching layer using a bonding material.
9. The ultrasonic transducer stack of claim 8 , wherein the bonding material forms a bondline layer between the first matching layer and the second matching layer.
10. The ultrasonic transducer stack of claim 9 , wherein the bondline layer has an elevational thickness of less than about 5 microns.
11. The ultrasonic transducer stack of claim 9 , wherein the bondline layer has an elevational thickness of between about 1 micron to about 5 microns.
12. The ultrasonic transducer stack of claim 9 , wherein the bondline layer has an elevational thickness of between about 1 micron to about 3 microns.
13. An ultrasonic transducer assembly, comprising:
a piezoelectric layer having an upper surface, wherein the piezoelectric layer is configured to operate at a center frequency between 20 MHz and 60 MHz;
a lens layer having an upper surface and a lower surface, wherein the lens layer comprises polymethylpentene or thermo-set cross linked polystyrene;
a first matching layer having an upper surface and a lower surface, wherein the upper surface of the first matching layer is connected to the lower surface of the lens layer, wherein the first matching layer comprises cyanoacrylate and has a thickness approximately equal to ¼ of the wavelength of the center frequency of the piezoelectric layer; and
a second matching layer having an upper surface and a lower surface, wherein the lower surface of the second matching layer is in substantial overlying registration with the upper surface of the piezoelectric layer.
14. The ultrasonic transducer assembly of claim 13 , further comprising a layer of epoxy configured to bond the upper surface of the second matching layer and the lower surface of the first matching layer.
15. The ultrasonic transducer assembly of claim 14 wherein the layer of epoxy has a thickness of 5 microns or less.