Non-planar and non-symmetrical piezoelectric crystals and reflectors

Abstract

An acoustophoretic device is disclosed. The acoustophoretic device includes an acoustic chamber, an ultrasonic transducer, and a reflector. The ultrasonic transducer includes a piezoelectric material driven by a voltage signal to create a multi-dimensional acoustic standing wave in the acoustic chamber emanating from a non-planar face of the piezoelectric material. A method for separating a second fluid or a particulate from a host fluid is also disclosed. The method includes flowing the mixture through an acoustophoretic device. A voltage signal is sent to drive the ultrasonic transducer to create the multi-dimensional acoustic standing wave in the acoustic chamber such that the second fluid or particulate is continuously trapped in the standing wave, and then agglomerates, aggregates, clumps, or coalesces together, and subsequently rises or settles out of the host fluid due to buoyancy or gravity forces, and exits the acoustic chamber.

What is claimed is: 
     
         1 . An acoustic reflector, comprising a reflective portion for reflecting acoustic energy, the reflective portion including a non-planar face that is faceted. 
     
     
         2 . The reflector of  claim 1 , further comprising a planar face opposite the non-planar face. 
     
     
         3 . The reflector of  claim 2 , further comprising the reflective portion being composed of piezoelectric material. 
     
     
         4 . The reflector of  claim 3 , further comprising the piezoelectric material being poled in a direction substantially perpendicular to the planar face of the reflector. 
     
     
         5 . The reflector of  claim 1 , wherein the non-planar face of the reflector includes a shape that is defined by a step function or a smooth function. 
     
     
         6 . The reflector of  claim 2 , wherein the non-planar face of the reflector includes a plurality of adjoining portions, each of which are located at respective distances from a respective closest portion of the planar face, the respective distances being different. 
     
     
         7 . The reflector of  claim 6 , wherein the respective distance of each adjoining portion from the respective closest portion of the planar face defines a resonance for the acoustic energy. 
     
     
         8 . The reflector of  claim 7 , wherein the collective respective distances define a plurality of distinct resonances that match resonances for the acoustic energy as resonance conditions for the acoustic energy vary. 
     
     
         9 . The reflector of  claim 1 , further comprising the faceted non-planar face being configured to scatter the reflected acoustic energy. 
     
     
         10 . The reflector of  claim 9 , further comprising the faceted non-planar face being configured to disrupt resonance of the acoustic energy. 
     
     
         11 . A method for forming an acoustic field, comprising:
 generating acoustic energy using an ultrasonic transducer;   reflecting the acoustic energy with an acoustic reflector that comprises a reflective portion for reflecting acoustic energy, the reflective portion including a non-planar face that is faceted; and   causing the generated acoustic energy and reflected acoustic energy to interact to form the acoustic field.   
     
     
         12 . The method of  claim 11 , wherein the acoustic reflector further comprises a planar face opposite the non-planar face. 
     
     
         13 . The method of  claim 12 , wherein the reflective portion further comprises piezoelectric material. 
     
     
         14 . The method of  claim 13 , further comprising the piezoelectric material being poled in a direction substantially perpendicular to the planar face of the reflector. 
     
     
         15 . The method of  claim 11 , further comprising defining a shape of the non-planar face of the reflector by a step function or a smooth function. 
     
     
         16 . The method of  claim 12 , wherein the non-planar face of the reflector includes a plurality of adjoining portions, each of which are located at respective distances from a respective closest portion of the planar face, the respective distances being different. 
     
     
         17 . The method of  claim 11 , further comprising scattering the reflected acoustic energy using the faceted non-planar face. 
     
     
         18 . The method of  claim 11 , further comprising disrupting resonance of the acoustic field using the faceted non-planar face. 
     
     
         19 . An acoustic system, comprising:
 an acoustic chamber;   an ultrasonic transducer coupled to the acoustic chamber that includes a piezoelectric material that is configured to be excited to generate an acoustic wave in the acoustic chamber; and   a reflector located across the acoustic chamber from the at least one ultrasonic transducer, the reflector including a faceted surface that faces the at least one ultrasonic transducer.   
     
     
         20 . The system of  claim 19 , wherein the faceted, non-planar face of the reflector includes a plurality of facet clusters. 
     
     
         21 . The system of  claim 19 , wherein the faceted, non-planar face of the reflector includes a plurality of wells.