Acoustic waveguide array
An acoustic (sound or ultrasound) wave transmitter having a plurality of waveguides is described, and a method of making such a transmitter is described. Each waveguide can have a cladded core. The cladded core is capable of transmitting acoustic wave energy from a first end surface to a second end surface of the cladded core. The waveguides can be substantially fixed relative to each other by a binder. The binder can be formed by fusing the claddings together, potting a material between the waveguides and/or mechanically holding the waveguides.
1. An ultrasonic wave transmitter, comprising:
a plurality of ultrasonic waveguides, each ultrasonic waveguide having a core and cladding, the core comprising (a) a first end surface, (b) a second end surface, and (c) a longitudinal surface extending between the first and second end surfaces, the longitudinal surface being substantially surrounded by the cladding to form a cladded core, wherein the core comprises a material having a first shear-wave propagation velocity (“SWPV”), and the cladding comprises polymethylmethacrylate having a second shear-wave propagation velocity, and wherein the second SWPV is greater than the first SWPV;
a binder holding the ultrasonic waveguides so as to substantially fix each ultrasonic waveguide relative to the other ultrasonic waveguides.
2. The ultrasonic wave transmitter of claim 1 , wherein the ultrasonic waveguides are substantially the same length.
3. The ultrasonic wave transmitter of claim 1 , wherein the first end surfaces of the ultrasonic waveguides lie substantially in a plane.
4. The ultrasonic wave transmitter of claim 1 , wherein the second end surfaces of the ultrasonic waveguides lie substantially in a plane.
5. The ultrasonic wave transmitter of claim 1 , wherein the binder is a material substantially the same as the material used for the cladding.
6. The ultrasonic wave transmitter of claim 5 , wherein the cladding material also serves as the binder and the binder has been formed by fusing the cladding of a first ultrasonic waveguide to the cladding of a second ultrasonic waveguide.
7. The ultrasonic wave transmitter of claim 1 , wherein the binder has been potted to interstices between the ultrasonic waveguides.
8. The ultrasonic wave transmitter of claim 1 , wherein the core is polymethylmethacrylate.
9. The ultrasonic wave transmitter of claim 1 , wherein the core is polyethylene.
10. The ultrasonic wave transmitter of claim 1 , wherein the core is a polymer and the core has an internal preload so as to be compressively contained within the cladding.
11. A method of making an ultrasonic acoustic wave transmitter, comprising:
providing a plurality of ultrasonic waveguides each having a core and cladding that are in intimate contact with each other at their interfacial surfaces, wherein, (a) the core has (i) a first end surface, (ii) a second end surface, and (iii) a longitudinal surface extending between the first and second end surfaces, the core having a first shear-wave propagation velocity (“SWPV”); (b) the cladding substantially surrounds the core to form a cladded core, the cladding comprising polymethylmethacrylate and having a second SWPV,
wherein the second SWPV is greater than the first SWPV;
binding the ultrasonic waveguides so as to substantially fix each ultrasonic waveguide relative to the other ultrasonic waveguides.
12. The method of claim 11 , wherein the ultrasonic waveguides that are provided are made substantially the same length by cutting the ultrasonic waveguides to a desired length.
13. The method of claim 11 , wherein binding is carried out by heating the ultrasonic waveguides to fuse the cladding of at least one ultrasonic waveguide to the cladding of another ultrasonic waveguide.
14. The method of claim 11 , wherein binding is carried out by placing a potting material between the ultrasonic waveguides.
15. The method of claim 11 , wherein binding is carried out by placing a band around the plurality of ultrasonic waveguides.
16. The method of claim 11 , further comprising cutting the bound ultrasonic waveguides so that the first end surfaces of the ultrasonic waveguides lie substantially in a plane.
17. The method of claim 16 , further comprising cutting the bound ultrasonic waveguides so that the second end surfaces of the ultrasonic waveguides lie substantially in a plane.
18. The method of claim 11 , wherein the core is polymethylmethacrylate.
19. The method of claim 11 , wherein the core is polyethylene.
20. The method of claim 11 , wherein the core is a polymer, and the core has an internal preload so as to be compressively contained within the cladding.
21. The ultrasonic wave transmitter of claim 1 wherein the plurality of ultrasonic waveguides are adapted to reduce scattering in an ultrasonic energy pulse.
22. The ultrasonic wave transmitter of claim 1 wherein each ultrasonic waveguide is adapted to cause an ultrasonic wave traveling therethrough to be substantially contained in the waveguide due to total internal reflection at the interface of the core and cladding.
23. The ultrasonic wave transmitter of claim 1 , wherein the core is polystyrene.
24. The method of claim 11 , wherein the core is polystyrene and the cladding is polymethylmethacrylate.