Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > All done with mirrors: NIST microscope tracks nanoparticles in 3-D

Heart of the orthogonal tracking microscope system developed at NIST is this nanoparticle solution sample well etched in silicon. Careful orientation of the silicon crystal makes it possible to chemically etch angled sides in the well so smooth they act as mirrors. In this configuration, four side views of a nanoparticle floating in solution (left) are reflected up. A microscope above the well sees the real particle (center, right) and four reflections that show the particle's vertical position.

Credit: NIST
Heart of the orthogonal tracking microscope system developed at NIST is this nanoparticle solution sample well etched in silicon. Careful orientation of the silicon crystal makes it possible to chemically etch angled sides in the well so smooth they act as mirrors. In this configuration, four side views of a nanoparticle floating in solution (left) are reflected up. A microscope above the well sees the real particle (center, right) and four reflections that show the particle's vertical position.
Credit: NIST

Abstract:
A clever new microscope design allows nanotechnology researchers at the National Institute of Standards and Technology (NIST) to track the motions of nanoparticles in solution as they dart around in three dimensions. The researchers hope the technology, which NIST plans to patent, will lead to a better understanding of the dynamics of nanoparticles in fluids and, ultimately, process control techniques to optimize the assembly of nanotech devices.

All done with mirrors: NIST microscope tracks nanoparticles in 3-D

GAITHERSBURG, MD | Posted on March 11th, 2008

While some nanoscale fabrication techniques borrow from the lithography and solid state methods of the microelectronics industry, an equally promising approach relies on "directed self-assembly." This capitalizes on physical properties and chemical affinities of nanoparticles in solutions to induce them to gather and arrange themselves in desired structures at desired locations. Potential products include extraordinarily sensitive chemical and biological sensor arrays, and new medical and diagnostic materials based on "quantum dots" and other nanoscale materials. But when your product is too small to be seen, monitoring the assembly process is difficult.

Microscopes can help, but a microscope sees a three-dimensional fluid volume as a 2-D plane. There's no real sense of the "up and down" movement of particles in its field of view except that they get more or less fuzzy as they move across the plane where the instrument is in focus. To date, attempts to provide a 3-D view of the movements of nanoparticles in solution largely have relied on that fuzziness. Optics theory and mathematics can estimate how far a particle is above or below the focal plane based on diffraction patterns in the fuzziness. The math, however, is extremely difficult and time consuming and the algorithms are imprecise in practice.

One alternative, NIST researchers reported at the annual meeting of the American Physical Society,* is to use geometry instead of algebra. Specifically, angled side walls of the microscopic sample well act as mirrors to reflect side views of the volume up to the microscope at the same time as the top view. (The typical sample well is 20 microns square and 15 microns deep.) The microscope sees each particle twice, one image in the horizontal plane and one in the vertical. Because the two planes have one dimension in common, it's a simple calculation to correlate the two and figure out each particle's 3-D path. "Basically, we reduce the problem of tracking in 3-D to the problem of tracking in 2-D twice," explains lead author Matthew McMahon.

The 2-D problem is simpler to solve—several software techniques can calculate and track 2-D position to better than 10 nanometers. Measuring the nanoparticle motion at that fine scale—speeds, diffusion and the like—will allow researchers to calculate the forces acting on the particles and better understand the basic rules of interaction between the various components. That in turn will allow better design and control of nanoparticle assembly processes.

* M. McMahon, A. Berglund, P. Carmichael, J. McClelland and J.A. Liddle. Orthogonal tracking microscopy for nanofabrication research. Paper presented on Monday, March 10, 2008, 1:03 p.m., at the 2008 March Meeting of the American Physical Society, New Orleans, La., March 10-14, 2008.

####

About NIST
From automated teller machines and atomic clocks to mammograms and semiconductors, innumerable products and services rely in some way on technology, measurement, and standards provided by the National Institute of Standards and Technology.

Founded in 1901, NIST is a non-regulatory federal agency within the U.S. Department of Commerce. NIST's mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.

For more information, please click here

Contacts:
Michael Baum

301-975-2763

Copyright © NIST

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Chemical trickery corrals 'hyperactive' metal-oxide cluster December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Exotic insulator may hold clue to key mystery of modern physics: Johns Hopkins-led research shows material living between classical and quantum worlds December 8th, 2016

Imaging

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Discoveries

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Announcements

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Tools

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Controlled electron pulses November 30th, 2016

Scientists shrink electron gun to matchbox size: Terahertz technology has the potential to enable new applications November 25th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project