High frequency piezocomposite transducer pillars
A transducer with triangular cross-sectional shaped pillars is described for suppressing lateral modes within a composite, and a method for producing the same. According to one aspect of the present application, a plurality of triangular cross-sectional shaped pillars extends outwardly from a substrate and form an array of pillars. The resulting array of pillars is configured to suppress the lateral modes of the transducer at higher operating frequencies, such as, at or above 15 MHz, at or above 20 MHz, or at or above 30 MHz.
1. A transducer, comprising:
a transducer substrate having a longitudinal axis, wherein the substrate is configured to operate at ultrasound frequencies at or above 15 MHz; and
a rectangular array of groups of pillars extending outwardly from the substrate, wherein the groups are arranged in adjacent rows that extend substantially parallel to the longitudinal axis, wherein each group includes at least first and second pillars having a triangular cross-section, and wherein the first and second pillars are separated by a first kerf oriented at a first angle not parallel or perpendicular to the longitudinal axis of the substrate.
2. The transducer of claim 1 wherein the groups of pillars are separated by a plurality of second kerfs and third kerfs, wherein the second kerfs are substantially perpendicular to the third kerfs.
3. The transducer of claim 2 wherein a width of the first kerf is substantially the same as a width of the second kerf.
4. The transducer of claim 2 wherein at least a portion of the first kerfs, the second kerfs, or the third kerfs is at least partially filled with a fill material.
5. The transducer of claim 4 wherein the fill material is a loaded epoxy.
6. The transducer of claim 4 wherein the fill material is a photoresist material.
7. The transducer of claim 1 wherein the substrate is flexible.
8. The transducer of claim 1 wherein the substrate is curved in cross-section such that the transducer is geometrically curved.
9. The transducer of claim 1 wherein the substrate and the groups of pillars is formed from a piezoelectric material.
10. The transducer of claim 9 wherein the piezoelectric material is lead zirconate titanate.
11. The transducer of claim 1 wherein the first angle is 45 degrees.
12. A transducer, comprising:
a piezoelectric substrate having a longitudinal axis; and
a rectangular array of groups of pillars extending outwardly from the substrate, wherein each group includes a first pillar and at least a second pillar, wherein the first and second pillars are separated by a first kerf oriented at a first angle not parallel or perpendicular to the longitudinal axis of the substrate, wherein the groups of pillars are separated by second kerfs and third kerfs, and wherein the second kerfs are substantially perpendicular to the third kerfs.
13. The transducer of claim 12 wherein the first pillar and the second pillar have a triangular cross-section.
14. The transducer at claim 13 wherein at least a portion of the first kerfs, the second kerfs, or the third kerfs is at least partially filled with a fill material.
15. The transducer of claim 14 wherein the fill material is a loaded epoxy.
16. The transducer of claim 14 wherein the fill material is a photoresist material.
17. The transducer of claim 12 wherein the each group of pillars has a rectangular outer perimeter.
18. The transducer of claim 12 wherein the groups of pillars are configured to suppress lateral modes at transducer operating frequencies of at least 15 MHz.
19. The transducer of claim 12 wherein each pillar has a polygonal shape with an odd number of sides.
20. The transducer of claim 2 wherein the second kerfs are parallel to the longitudinal axis, and wherein the third kerfs are perpendicular to the longitudinal axis.
21. A high-frequency ultrasound transducer, comprising:
a transducer substrate having a longitudinal axis; and
an array of groups of pillars extending outwardly from the substrate, wherein each group includes a first pillar and at least a second pillar, wherein the first and second pillars are separated by a first kerf oriented at a first angle not parallel or perpendicular to the longitudinal axis of the substrate, wherein each pillar has a base and an apex, and wherein a distance between the base and the apex ranges from between about 5 microns to about 70 microns.