Trapped particle classification in additive manufacturing

This technology is an improvement to a rapid design approach for designing nanophotonic devices. It is a method of optical positioning and linking (OPAL) using highly focused lasers (sometimes called “optical tweezers”) used for nanofabrication of molecules for devices, drugs, and other nano-metamaterials. 

Combined with the previous optical positioning and linking invention, it could enable the creation of significantly larger and more complex nanophotonic devices, consisting of many thousands of microscale or nanoscale building blocks. It can also be used as a method of automating 3D additive manufacturing of heterogeneous nanostructured materials and devices. 

Background: 
The previous invention used optical tweezers to position micro and nanoscale building blocks that were linked together using biochemical linker molecules to assemble nanophotonic metamaterials and devices. OPAL offered the potential for particularly high resolution and multi-material integration compared to other existing 3D nanofabrication tools. 

Previously, OPAL was semi-automated in that while the positioning of the building blocks was automated via computer control, the loading of particles into the optical trap was not. It was done by the operator manually “fishing” for particles using the optical tweezer.

The current invention is a method of fully automating the approach using the back-scattered optical signal to ensure that a single particle of the desired size is trapped. More specifically, the signal will be used to determine whether zero, one, or more particles of a given size are in the trap. The computer will then act accordingly to ensure the right particle is brought to the right location.

Applications: 

• Optical tweezers
• Air quality monitoring
• Additive manufacturing
• Micro and nanoscale building 
• Particle classification/counting

Advantages: 

• Optical positioning and linking using highly focused lasers, also called optical tweezers, is useful for precise nanofabrication of devices, drugs, and other nano-metamaterials
• Automated 3D additive manufacturing of heterogeneous nanostructured materials and devices