System and method for tunable patterning and assembly of particles via acoustophoresis

Abstract

A method of ordering particles suspended in a solution includes providing anisotropic particles suspended in a solution to a channel, wherein the anisotropic particles are unordered when entering the channel. The method further includes applying sound waves to the channel, wherein the frequency of the sound wave is tuned to create one or more columns of particles oriented in the same direction.

1 . A method of ordering particles suspended in a solution, the method comprising:
 providing anisotropic particles suspended in a solution to a channel, wherein the anisotropic particles are unordered when entering the channel; and   applying sound waves to the channel, wherein the frequency of the sound wave is tuned to create one or more columns of anisotropic particles oriented in the same direction.   
     
     
         2 . The method of  claim 1 , wherein an output of the channel is bifurcated such that anisotropic particles organized into one or more columns of anisotropic particles located in a center of the channel are directed to a first outlet and particles located outside of the center of the channel are directed to a second outlet. 
     
     
         3 . The method of  claim 1 , wherein the sound waves applied to the channel force the anisotropic particles to a pressure node of the sound wave, and wherein scattering forces act on the anisotropic particles to align them end-to-end. 
     
     
         4 . The method of  claim 1 , further including:
 photocuring the one or more columns of anisotropic particles to preserve the ordering and orientation of the one or more columns of anisotropic particles, wherein the solution is a hydrogel solution.   
     
     
         5 . The method of  claim 1 , further including:
 thermally curing the one or more columns of anisotropic particles to preserve the ordering and orientation of the one or more columns of anisotropic particles, wherein the solution is an epoxy-type solution.   
     
     
         6 . The method of  claim 1 , wherein the solution is a chaotropic solution dispersed with macromolecules that bind with the one or more columns of anisotropic particles to promote particle cohesion to preserve the ordering and orientation of the one or more columns of anisotropic particles. 
     
     
         7 . The method of  claim 1 , wherein applying sound waves to the channel includes applying sound waves in a first stage to extract a high concentration of anisotropic particles from the solution, and applying sound waves in a second stage to order the extracted anisotropic particles into a desired configuration. 
     
     
         8 . The method of  claim 1 , further including depositing the one or more columns of oriented anisotropic particles via a printhead. 
     
     
         9 . An apparatus for delivering ordered particles to a printhead of a three-dimensional printer, the apparatus comprising:
 a acoustophoresis device having at least a first inlet, at least a first outlet, and a channel defined between the first inlet and the first outlet; and   a first piezoelectric device adhered to a surface of the acoustophoresis device to generate sound waves within at least a first portion of the channel,   wherein a solution comprising anisotropic particles is delivered to the at least first inlet and wherein the anisotropic particles are organized into one or more columns along an axis parallel to a direction of flow of the solution by standing acoustic waves generated by the piezoelectric device, wherein the at least one column of anisotropic particles is aligned with the first outlet, and wherein the first outlet is in fluid communication with the printhead to deliver one or more columns of ordered, anisotropic particles to the printhead.   
     
     
         10 . The apparatus of  claim 9 , wherein the acoustophoresis device further includes a waste outlet, wherein anisotropic particles organized into one or more columns within a center of the channel are provided to the first outlet and wherein excess solution is provided to the waste outlet. 
     
     
         11 . The apparatus of  claim 9 , wherein the acoustophoresis device includes a first stage and a second stage, wherein the first stage includes the at least first inlet and the first outlet, and wherein the second stage includes at least a second inlet and a second outlet, wherein the at least second inlet is in fluid communication with the first outlet of the first stage and wherein the second outlet is in fluid communication with the printhead. 
     
     
         12 . The apparatus of  claim 11 , further including a second piezoelectric device adhered to a surface of the acoustophoresis device to generate sound waves within the second stage of the acoustophoresis device, wherein the first piezoelectric device generates sound waves within the first stage of the acoustophoresis device. 
     
     
         13 . The apparatus of  claim 9 , wherein the solution in which the anisotropic particles are suspended is an epoxy-type solution, and wherein the apparatus further includes a thermal curing element located upstream of the printhead, wherein the thermal curing element thermally cures the epoxy-type solution to preserve the organization of the anisotropic particles. 
     
     
         14 . The apparatus of  claim 9 , wherein the solution in which the anisotropic particles are suspended is a hydrogel solution, and wherein the apparatus further includes a photo-curing window located upstream of the printhead, wherein the photo-curing window allows incident light to cure the hydrogel solution to preserve the organization of the anisotropic particles. 
     
     
         15 . A method of providing ordered particles to a printhead of a three-dimensional printer, the method comprising:
 providing anisotropic particles suspended in a solution to an inlet of an acoustophoresis device, wherein the acoustophoresis device includes the at least one inlet, a primary outlet, a waste outlet, and a channel disposed between the at least one inlet and the primary outlet;   applying sound waves to the channel of the acoustopheresis device to order the anisotropic particles in one or more columns along an axis parallel to a flow of solution through the channel, wherein the anisotropic particles are oriented in the same direction as one another within the channel;   receiving at the outlet one or more ordered columns of anisotropic particles; and   providing the one or more ordered columns of anisotropic particles received at the outlet to the printhead for deposition   
     
     
         16 . The method of  claim 15 , wherein the acoustophoresis device further includes a first stage in fluid communication with the at least one inlet, an intermediate outlet, and one or more waste outlets, wherein sound waves applied to the first stage order the anisotropic particles in one or more columns, wherein the ordered anisotropic particles are provided to the intermediate outlet while excess solution is provided to the waste outlets. 
     
     
         17 . The method of  claim 16 , wherein the acoustophoresis device further includes a second stage in fluid communication with the intermediate outlet, wherein sound waves applied to the second stage order the anisotropic particles in one or more columns, wherein the ordered anisotropic particles are provided to the primary outlet. 
     
     
         18 . The method of  claim 17 , wherein sound waves applied to the first stage are generated by a first piezoelectric device and second waves applied to the second stage are generated by a second piezoelectric device. 
     
     
         19 . The method of  claim 15 , further including:
 photocuring the one or more columns of anisotropic particles to preserve the ordering and orientation of the one or more columns of anisotropic particles, wherein the solution is a hydrogel solution.   
     
     
         20 . The method of  claim 15 , further including:
 thermally curing the one or more columns of anisotropic particles to preserve the ordering and orientation of the one or more columns of anisotropic particles, wherein the solution is an epoxy-type solution.