High Frequency Piezocomposite And Methods For Manufacturing Same

Abstract

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 substrate having a longitudinal axis;   a plurality of pillars extending outwardly therefrom the substrate, wherein the plurality of pillars forms an array of pillars positioned in adjacent rows, each row of the array of pillars extending substantially parallel to the longitudinal axis of the substrate;   a means for suppressing the lateral modes of the transducer at operating frequencies at or above 15 MHz, wherein the means for suppressing the lateral modes comprises each pillar having a triangular cross-sectional shape that has an apex, an opposed base having opposed edges, and a pair of side walls that extend from the apex to the respective edges of the base, wherein the array of pillars comprises a plurality of paired pillars, wherein each of the paired pillars comprises a first pillar positioned adjacent to a second pillar such that the base of the first pillar is spaced from and substantially opposes the base of the second pillar, and wherein each row of the array of pillars comprises a plurality of paired pillars that are positioned adjacent each other such that one side wall of the first pillar is spaced from and substantially opposes one side wall of the second pillar.   
   
   
       2 . The transducer of  claim 1 , wherein the array of pillars defines a plurality of first troughs extending substantially parallel to the longitudinal axis of the substrate, a plurality of second troughs extending substantially transverse to the longitudinal axis of the substrate, and a plurality of third troughs extending at an acute angle relative to the longitudinal axis of the substrate. 
   
   
       3 . The transducer of  claim 2 , wherein the width of the first trough is substantially the same as the width of the second trough. 
   
   
       4 . The transducer of  claim 3 , wherein the width of the second trough is substantially the same as the width of the third trough. 
   
   
       5 . The transducer of  claim 2 , wherein at least a portion of the respective first, second, and third troughs is at least partially filled with a fill material. 
   
   
       6 . The transducer of  claim 5 , wherein the fill material is a loaded epoxy. 
   
   
       7 . The transducer of  claim 5 , wherein the fill material is a photoresist material. 
   
   
       8 . The transducer of  claim 2 , wherein the substrate is flexible. 
   
   
       9 . The transducer of  claim 2 , wherein the substrate is curved in cross-section such that the transducer is geometrically curved. 
   
   
       10 . The transducer of  claim 2 , wherein the substrate and the plurality of pillars is formed from a piezoelectric material. 
   
   
       11 . The transducer of  claim 10 , wherein said piezoelectric material is lead zirconate titanate. 
   
   
       12 . The transducer of  claim 2 , wherein the substrate and the plurality of pillars is formed from a single-crystal piezoelectric. 
   
   
       13 . A method of producing an ultrasonic wave emission pattern at operating frequencies at or above 15 MHz, comprising:
 applying an electric signal to a piezoelectric substrate of a transducer having a plurality of pillars extending outwardly therefrom the substrate, wherein the plurality of pillars forms an array of pillars positioned in adjacent rows, each row of the array of pillars extending substantially parallel to a longitudinal axis of the substrate; and   suppressing the lateral modes of the transducer by providing each pillar with a triangular cross-sectional shape that has an apex, an opposed base having opposed edges, and a pair of side walls that extend from the apex to the respective edges of the base, wherein the array of pillars comprises a plurality of paired pillars, wherein each of the paired pillars comprises a first pillar positioned adjacent to a second pillar such that the base of the first pillar is spaced from and substantially opposes the base of the second pillar, and wherein each row of the array of pillars comprises a plurality of paired pillars that are positioned adjacent each other such that one side wall of the first pillar is spaced from and substantially opposes one side wall of the second pillar.   
   
   
       14 . The method of  claim 13 , wherein the array of pillars defines a plurality of first troughs extending substantially parallel to the longitudinal axis of the substrate, a plurality of second troughs extending substantially transverse to the longitudinal axis of the substrate, and a plurality of third troughs extending at an acute angle relative to the longitudinal axis of the substrate. 
   
   
       15 . The method of  claim 14 , wherein the width of the respective first, second and third troughs are substantially equal. 
   
   
       16 . The method of  claim 14 , wherein at least a portion of the respective first, second, and third troughs is filled with a fill material. 
   
   
       17 . The method of  claim 13 , wherein the substrate is flexible. 
   
   
       18 . A transducer for emitting energy at operating frequencies at or above 15 MHz in response to an input signal, the transducer comprising:
 a plurality of pillars for emitting energy in response to the input signal applied thereto, wherein the plurality of pillars are positioned in adjacent, substantially parallel rows, wherein each pillar has a triangular cross-sectional shape for suppressing the lateral modes at the operating frequencies, each pillar having an apex, an opposed base having opposed edges, and a pair of side walls that extend from the apex to the respective edges of the base, wherein the plurality of pillars comprises a plurality of paired pillars, wherein each of the paired pillars comprises a first pillar positioned adjacent to a second pillar such that the base of the first pillar is spaced from and substantially opposes the base of the second pillar, and wherein each row of the array of pillars comprises a plurality of paired pillars that are positioned adjacent each other such that one side wall of the first pillar is spaced from and substantially opposes one side wall of the second pillar.   
   
   
       19 . The transducer of  claim 18 , further comprising a curved substrate, and wherein the plurality of pillars extends outwardly therefrom the substrate. 
   
   
       20 . The transducer of  claim 19 , wherein the substrate and the plurality of pillars form an electrically monolithic structure that is configured for emitting energy in response to the input signal. 
   
   
       21 . The transducer of  claim 19 , wherein the array of pillars defines a plurality of first troughs extending substantially parallel to a longitudinal axis of the substrate, a plurality of second troughs extending substantially transverse to the longitudinal axis of the substrate, and a plurality of third troughs extending at an acute angle relative to the longitudinal axis of the substrate. 
   
   
       22 . The transducer of  claim 21 , wherein the width of the respective first, second, and third troughs are substantially equal. 
   
   
       23 . The transducer of  claim 21 , wherein at least a portion of the respective first, second, and third troughs is filled with a fill material. 
   
   
       24 . A transducer, comprising:
 a substrate having a longitudinal axis;   a plurality of pillars extending outwardly therefrom the substrate, wherein the plurality of pillars forms an array of pillars positioned in adjacent rows, each row of the array of pillars extending substantially parallel to the longitudinal axis of the substrate;   a means for suppressing the lateral modes of the transducer at operating frequencies at or above 15 MHz, wherein the means for suppressing the lateral modes comprises each pillar having a triangular cross-sectional shape that has an apex, an opposed base having opposed edges, and a pair of side walls that extend from the apex to the respective edges of the base, wherein the array of pillars defines a plurality of first troughs extending substantially parallel to the longitudinal axis of the substrate, a plurality of second troughs extending substantially transverse to the longitudinal axis of the substrate, a plurality of third troughs extending at about a 45° angle relative to the longitudinal axis of the substrate, and a plurality of fourth troughs extending substantially transverse to the third troughs.   
   
   
       25 . The transducer of  claim 24 , wherein the width of the first trough is substantially the same as the width of the second trough. 
   
   
       26 . The transducer of  claim 25 , wherein the width of the second trough is substantially the same as the width of the third trough. 
   
   
       27 . The transducer of  claim 26 , wherein the width of the third trough is substantially the same as the width of the fourth trough. 
   
   
       28 . The transducer of  claim 24 , wherein at least a portion of the respective first, second, third and fourth troughs is filled with a fill material. 
   
   
       29 . The transducer of  claim 28 , wherein the fill material is a loaded epoxy. 
   
   
       30 . The transducer of  claim 28 , wherein the fill material comprises a photoresist material. 
   
   
       31 . The transducer of  claim 24 , wherein the substrate is flexible. 
   
   
       32 . The transducer of  claim 24  wherein the substrate is curved in cross-section such that the transducer is geometrically curved. 
   
   
       33 . The transducer of  claim 24 , wherein the substrate and the plurality of pillars is formed from a piezoelectric material. 
   
   
       34 . The transducer of  claim 33 , wherein said piezoelectric material is lead zirconate titanate. 
   
   
       35 . The transducer of  claim 33 , wherein the substrate and the plurality of pillars is formed from a single-crystal piezoelectric.