Carbon Nanotube Collimator Ideal for Focused Ion Beams To Deliver Nano-Beams of Charged Particles

The University of Central Florida Research Foundation, Inc. (Orlando, FL) and The Regents of the University of California (Oakland, CA) share the rights to U.S. Patent 7,750,297 for a carbon nanotube collimator, its fabrication and application

A collimator is a device that narrows a beam of particles or waves. To "narrow" can mean either to cause the directions of motion to become more aligned in a specific direction (i.e. collimated  or parallel) or to cause the spatial cross section of the beam to become smaller.

Inventors Lee Chow (Orlando, FL), Guangyu Chai  (Orlando, FL) and Thomas Schenkel (San Francisco, CA) developed apparatus, methods, systems and devices for fabricating individual CNT collimators. Micron size fiber coated CNT samples are synthesized with chemical vapor deposition method and then the individual CNT collimators are fabricated with focused ion beam technique. Unfocused electron beams are successfully propagated through the CNT collimators.

The CNT nano-collimators are used for applications including single ion implantation and in high-energy physics, and allow rapid, reliable testing of the transmission of CNT arrays for transport of molecules.

A method for producing a carbon nanotube collimator comprises the steps of: providing a fiber coated carbon nanotube on a substrate; detaching the carbon nanotube from the substrate to produce a CNT collimator; moving the detached CNT collimator to a transmission electron microscopy grid using a micro-manipulator; attaching the CNT collimator to the transmission electron microscopy grid; using a low ion beam current to thin the CNT collimator to a predetermined CNT collimator channel length; and using the low ion beam current to clean a surface of the CNT collimator, wherein the CNT collimator is used for applications where a narrow, well-collimated beam of charged particles is required.

Carbon nanotubes (CNT), with their hollow channel along the axis, are ideal collimators for the formation of nano-beams of charged particles, and they allow transport of neutral molecules for delivery to specific locations. The present invention shows that a focused ion beam (FIB) technique can be used to fabricate carbon nanotube collimators and the channeling of electron beam through carbon nanotube collimator is we experimentally verified. This nano-collimator may have important applications in single ion implantation, high energy physics, and as a production and screening tool for integration of CNT based drug delivery systems.