Available Technology

OPTICAL DEVICE FOR SORTING PARTICLES BY SIZE

Sorting is prerequisite  to measurement, analysis, and detection of particles. This invention sorts aerosol or colloidal particles by size using optical forces. It consists of a laser-pumped optical cavity that establishes a relatively large, high-intensity standing-wave optical field. Particles flowing  across the optical field  take different trajectories through the field based on particle size.  Particles exiting the optical field are dispersed in a direction perpendicular to the direction of flow. Sorting can be performed for particles in the size range 10 nm to 10 µm.

The invention differs from the dominant technology, the diffusion mobility analyzer (DMA), in that the method of sorting is based on optical not electric forces  and is more direct, i.e., requires fewer questionable assumptions.  It does not require modification of the particles as does the DMA. This enables measurement of more delicate particles, such as biological particles.

Particle sorting is used in a number of fields  including atmospheric monitoring, workplace air quality monitoring, nano-particle manufacturing, semiconductor manufacturing, pharmaceutical manufacturing, medical research, and homeland security.  With improvement in state-of-the-art, these capabilities could find  additional application in fields such as healthcare and forensics.

Sorting is prerequisite  to measurement, analysis, and detection of particles.

The invention sorts aerosol or colloidal particles by size using optical forces.  It consists of a laser-pumped optical cavity that establishes a relatively large, high-intensity standing-wave optical field.  Particles flowing  across the optical field  take different trajectories through the field based on particle size. Particles exiting the optical field  are dispersed in a direction perpendicular to the direction of flow. Sorting can be performed for particles in the size range 10 nm to 10 µm.

The invention differs from the dominant technology, the diffusion mobility analyzer (DMA), in that the method of sorting is based on optical not electric forces  and is more direct, i.e., requires fewer questionable assumptions.  It does not require modification of the particles as does the DMA. This enables measurement of more delicate particles, such as biological particles.

Particle sorting is used in a number of fields  including atmospheric monitoring, workplace air quality monitoring, nano-particle manufacturing, semiconductor manufacturing, pharmaceutical manufacturing, medical research, and homeland security.   

 

 

Abstract: 

The invention sorts particles by size over the range of 10 nm to 10 µm.  The invention consists of an intense standing wave optical field  created in a laser-pumped resonant optical cavity. Particles flowing  across the optical field  are dispersed perpendicular to the direction of flow according to particle size.  This dispersion remains even after the particles have left the optical field.  Sorting occurs real-time and can process a continuous stream of particles. The sorting is non-destructive. Performance  of the invention has been investigated with 2 different numerical models. The invention is applicable to both aerosol and colloidal particles.

Benefits: 

The invention is a complete break from what is currently being used. As such, it offers many potential advantages depending on application. Among these are higher resolution, absolute size determination, non-contact and non-destructive, and applicable in gas or liquid.

Inventors: 
John Curry and Zachary Levine
Patent Number: 
10,073,026
Technology Type(s): 
Homeland Security, Laser and Optics, Atomic Physics, Manufacturing, Health Care, Biochemical Science, Nanometrology, Nanotechnology, Optical Physics, Optical Technology
Internal Laboratory Ref #: 
16-012
Patent Issue Date: 
September 11, 2018
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