System and method for separating micro-particles

Abstract

A system and method for separating particles is disclosed in which the particles are exposed to a moving light intensity pattern which causes the particles to move at a different velocities based on the physical properties of the particles. This system and method allows particles of similar size and shape to be separated based on differences in the particles dielectric properties.

1 . A system for separating at least two particles, the particles having different physical properties, the system comprising:
 means for creating a non-trapping light intensity pattern in the vicinity of the at least two particles; and   means for moving the light intensity pattern with respect to the at least two particles.   
   
   
       2 . The system according to  claim 20 , wherein the means for creating a light intensity pattern comprises a light source for producing two light beams aimed to interfere with each other in the vicinity of the at least two particles. 
   
   
       3 . The system according to  claim 2 , wherein the light beams comprise coherent light beams. 
   
   
       4 . The system according to  claim 20 , further comprising a beam splitter and a reflector, wherein the light source is configured to produce a light beam aimed at the beam splitter, the beam splitter is configured to split the light beam into a first light beam directed toward the at least two particles and a second light beam directed toward the reflector, the reflector is configured to redirect the second light beam toward the at least two particles such that the first and second light beams interfere creating a light intensity pattern in the vicinity of the at least two particles. 
   
   
       5 . The system according to  claim 4 , wherein the means for moving comprises an actuator connected to the reflector for moving the reflector. 
   
   
       6 . The system according to  claim 4 , wherein the means for moving comprises an actuator connected to the light source and beam splitter for moving the light source and beam splitter. 
   
   
       7 . The system according to  claim 2 , wherein the means for moving is configured to move the light intensity pattern in space. 
   
   
       8 . The system according to  claim 2 , wherein the means for moving is configured to move the light intensity pattern in time. 
   
   
       9 . The system according to  claim 2 , wherein the means for moving is configured to fix the light intensity pattern and move the at least two particles in space relative to the light intensity pattern. 
   
   
       10 . The system according to  claim 9  further comprising a source of at least two particles in a medium, wherein the at least two particles are held on a slide and the means for moving comprises an actuator for moving the slide relative to the light intensity pattern. 
   
   
       11 . The system of  claim 2  wherein the means for moving comprises a phase modulator for modulating the phase of one of the two light beams with respect the other. 
   
   
       12 . The system of  claim 2  wherein the light source comprises a laser. 
   
   
       13 . The system of  claim 2  wherein the light beam has a wavelength between 0.3 μm and 1.8 μm. 
   
   
       14 . The system of  claim 2  wherein the light beam has a wavelength between 0.8 μm and 1.8 μm. 
   
   
       15 . The system of  claim 14  wherein the light beam has a wavelength of 1.55 μm. 
   
   
       16 . The system according to  claim 20 , wherein the means for creating a light intensity pattern comprises a light source and an optical mask, which can be a phase mask, an amplitude mask, or a holographic mask, the light source being configured for producing a light beam directed through the optical mask toward the at least two particles. 
   
   
       17 . The system of  claim 1  further comprising a plurality of light sources positioned adjacent to each other for producing a plurality of light beams directed toward the at least two particles for creating a light intensity pattern. 
   
   
       18 . The system of  claim 17  further comprising an actuator for moving the plurality of light sources. 
   
   
       19 . The system according to  claim 20 , wherein the plurality of light beams are aimed to slightly overlap each adjacent light beam in the vicinity of the at least two particles, the plurality of light sources being configured to be dimmed and brightened in a pattern for creating a moving light intensity pattern. 
   
   
       20 . The system according to  claim 1 , further comprising a source of at least two particles in a medium.