Article produced by acoustic cavitation in a liquid insonification medium

Abstract

An article produced by acoustic cavitation by controlling cavitation events in a liquid insonification medium utilizing a waveform to excite a transducer with a series of tone bursts having medium recovery intervals between respective bursts so that the medium repeatedly recovers from cavitation events between bursts. Articles include a device made from a semiconductor wafer that is cleaned or otherwise processed by acoustic cavitation, a surface having been de-coated by acoustic cavitation, a chemical compound made from a chemical substance reacted by acoustic cavitation, and recycled paper made from inked paper de-inked by cavitation. Cavitation events are generated using a transducer and a waveform generator, e.g., square wave tone bursts, to excite the transducer with a signal controlled in frequency, burst repetition rate, duty-cycle and/or amplitude, e.g., utilizing bursts having a frequency between 500 KHz and 10 MHz, and a duty cycle between 0.1% and 70%.

1 . An article produced by acoustic cavitation comprising the steps of: 
 providing a transducer,    providing a liquid insonification medium in which cavitation is induced,    coupling the transducer with the article through a continuum of the liquid insonification medium, and    energizing the transducer with a tone burst waveform having recovery intervals between respective bursts to produce a signal that co-acts with the transducer and the medium to generate on or about the article an acoustic field having multiple high frequency components and multiple lower frequency components whereby to perform an event relative to the article.    
     
     
         2 . The article produced according to  claim 1 , further comprising: 
 providing an impedance-modifying layer on the transducer to compensate for variance in acoustic properties between material of the transducer and the liquid insonification medium whereby to improve energy transfer between the transducer and the medium.    
     
     
         3 . The article produced according to  claim 2 , wherein the impedance-modifying layer has a thickness of about one-quarter wavelength of a component of the acoustic field generated by the transducer.  
     
     
         4 . The article produced according to  claim 2 , wherein the impedance-modifying layer comprises a polymeric material.  
     
     
         5 . The article produced according to  claim 1 , wherein the transducer is made from one of a lead titanate zirconate piezoelectric ceramic material and a lithium niobate material.  
     
     
         6 . The article produced according to  claim 1 , further including providing a non-fluid chamber on a side of the transducer opposite the medium.  
     
     
         7 . The article produced according to  claim 1 , further comprising: 
 controlling an extent of cavitation events generated by the transducer in accordance with a desired rate of work performed.    
     
     
         8 . The article produced according to  claim 1 , wherein the article includes a surface and the energizing step includes directing cavitation events upon a coating of the surface via a liquid coupling between the transducer and the surface in order to de-coat the coating on the surface.  
     
     
         9 . The article produced according to  claim 8 , wherein the liquid coupling is formed by a streaming jet providing a liquid communicating path between the transducer and the surface.  
     
     
         10 . The article produced according to  claim 1 , wherein the insonification medium comprises clean water, the article comprises a device made from a semiconductor wafer, and the energizing step includes directing cavitation events in the vicinity of the semiconductor wafer via liquid coupling between the transducer and the wafer in order to clean the wafer by evicting particulates therefrom.  
     
     
         11 . The article produced according to  claim 1 , wherein said article comprises a paper substrate having fused ink thereon and said energizing step includes directing cavitation events upon the paper substrate via an acoustic coupling between the transducer and the substrate in order to de-ink the substrate.  
     
     
         12 . The article produced according to  claim 1 , wherein the article comprises a chemical compound produced by reacting a chemical substance, and the energizing step includes directing cavitation events towards the substance in order to stimulate a liquid-based chemical reaction.  
     
     
         13 . The article produced according to  claim 1 , wherein the article comprises a surface and the energizing step includes directing cavitation events upon the surface via a liquid coupling between the transducer and the surface in order to remove a coating adhered to the surface.  
     
     
         14 . An article produced by a method of acoustic cavitation comprising: 
 providing an air-backed resonant mode transducer,    providing a liquid insonification medium in which cavitation is induced,    coupling the transducer and the article through a continuum of the liquid insonification medium,    energizing the transducer in a thickness direction with a tone burst waveform having recovery intervals between respective bursts of a frequency between 500 KHz and 10 MHz to produce a waveform that co-acts with the transducer and the medium to generate on or about the article an acoustic field having multiple high frequency components and multiple lower frequency components, and    controlling a duty cycle of the tone burst waveform between a range of 0.1% and 70%.    
     
     
         15 . The article produced according to the method of  claim 14 , wherein the method further comprises providing an impedance-matching layer on the resonant mode transducer.  
     
     
         16 . The article produced according to the method of  claim 15 , wherein the transducer comprises one of a polymeric material, a lithium niobate material, and a titanate zirconate material.  
     
     
         17 . The article produced according to the method of  claim 15 , wherein the bursts comprise a series of in-harmonic waves.  
     
     
         18 . An article produced by an acoustic cavitation method that comprises: 
 providing a resonant mode transducer,    providing a liquid insonification medium in which cavitation is induced,    coupling the transducer and the article through a continuum of the liquid insonification medium, and    energizing the transducer in a thickness direction with an in-harmonic tone burst signal having recovery intervals between respective bursts that allow the medium to recover from cavitation events whereby to produce a waveform that co-acts with the transducer and the medium to generate on or about the article an acoustic field having multiple high frequency components and multiple lower frequency components.    
     
     
         19 . The article produced according to  claim 18 , wherein the insonification medium comprises clean water, the article comprises a device made from a semiconductor wafer, and the energizing step includes directing cavitation events in the vicinity of the semiconductor wafer via liquid coupling between the transducer and the wafer in order to clean the wafer.  
     
     
         20 . The article produced according to  claim 18 , wherein the article comprises paper made from a paper substrate having fused ink thereon and the energizing step includes directing cavitation events upon the paper substrate via an acoustic coupling between the transducer and the substrate in order to de-ink the substrate.  
     
     
         21 . The article produced according to  claim 18 , wherein the article comprises paper made from paper pulp including fused ink thereon and the energizing step includes directing cavitation events towards the pulp via an acoustic coupling between the transducer and the pulp in order to de-ink the pulp.  
     
     
         22 . The article produced according to  claim 18 , further comprising: 
 providing an impedance-modifying layer on the transducer to compensate for variance in acoustic properties between material of said transducer and the liquid insonification medium whereby to improve energy transfer between the transducer and the medium.    
     
     
         23 . The article produced according to  claim 22 , wherein the impedance-modifying layer has a thickness of about one-quarter wavelength of a component of the acoustic field generated by the transducer.  
     
     
         24 . The article produced according to  claim 22 , wherein the impedance-modifying layer comprises a polymeric material.  
     
     
         25 . The article produced according to  claim 18 , wherein the transducer comprises one of a lead titanate zirconate piezoelectric ceramic material and a lithium niobate material.  
     
     
         26 . The article produced according to  claim 18 , further including providing a non-fluid chamber on a side of the transducer opposite the medium.  
     
     
         27 . The article produced according to  claim 18 , further comprising: 
 controlling an extent of cavitation events generated by the transducer in accordance with a desired rate of work performed.    
     
     
         28 . The article produced according to  claim 27 , further comprising controlling a duty cycle of the tone burst signal between 0.1% and about 70%.  
     
     
         29 . The article produced according to  claim 27 , further comprising providing a frequency of said tone burst between 500 KHz and 10 MHz.