Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > NIST Puts the Optical Microscope Under the Microscope to Achieve Atomic Accuracy

Illustration shows an array of apertures with a spacing of 5000 nanometers (nm) ± 1 nm. The apertures pass light through a metal film on a glass slide. Imaging the aperture array with an optical microscope results in apparent errors in the spacing between apertures. Knowledge of the true spacing allows correction of these imaging errors. This calibration process enables accurate measurements of position across a large image.
Credit: NIST
Illustration shows an array of apertures with a spacing of 5000 nanometers (nm) ± 1 nm. The apertures pass light through a metal film on a glass slide. Imaging the aperture array with an optical microscope results in apparent errors in the spacing between apertures. Knowledge of the true spacing allows correction of these imaging errors. This calibration process enables accurate measurements of position across a large image. Credit: NIST

Abstract:
Over the last two decades, scientists have discovered that the optical microscope can be used to detect, track and image objects much smaller than their traditional limit—about half the wavelength of visible light, or a few hundred nanometers.

NIST Puts the Optical Microscope Under the Microscope to Achieve Atomic Accuracy

Gaithersburg, MD | Posted on May 22nd, 2018

That pioneering research, which won the 2014 Nobel Prize in Chemistry, has enabled researchers to track proteins in fertilized eggs, visualize how molecules form electrical connections between nerve cells in the brain, and study the nanoscale motion of miniature motors.
Now, research developments at the National Institute of Standards and Technology (NIST) enable the microscopes to measure these nanometer-scale details with a new level of accuracy.
“We put the optical microscope under a microscope to achieve accuracy near the atomic scale,” said NIST’s Samuel Stavis, who served as the project leader for these efforts.
Because optical microscopes have not traditionally been used to study the nanometer scale, they typically lack the calibration—comparison to a standard to check that a result is correct—necessary to obtain information that is accurate at that scale. A microscope may be precise, consistently indicating the same position for a single molecule or nanoparticle. Yet, at the same time, it can be highly inaccurate—the location of the object identified by the microscope to within a billionth of a meter may, in fact, be millionths of a meter off due to unaccounted-for errors. “Precision without accuracy can be very misleading,” said Jon Geist, a NIST co-author of the study.
To address the problem, NIST has developed a new calibration process that closely examines and corrects these imaging errors. The process uses reference materials—objects with characteristics that are well-known and stable—that have the potential for mass production and widespread distribution to individual laboratories.
This is important because optical microscopes are common laboratory instruments that can easily magnify different samples, ranging from delicate biological specimens to electrical and mechanical devices. As well, optical microscopes are becoming increasingly capable and economical as they incorporate scientific versions of the lights and cameras in smartphones.
The NIST team relied on nanometer-scale fabrication processes to develop the reference material. The researchers used electron beams and ion milling to form an array of pinhole apertures through a thin film of platinum on a glass slide. The process enabled the team to space the apertures 5,000 nanometers apart, to within an accuracy of about 1 nanometer. In this way, the researchers built a measure of accuracy into the aperture positions.
Shining light through the array of apertures creates an array of points for imaging. But because all microscope lenses have imperfections, errors inevitably occur during imaging that change the apparent positions of the points, making the spacing between the apertures appear to be larger or smaller than the actual spacing engineered by the team. Knowledge of the true spacing allows correction of the imaging errors and calibration of the microscope for measurements of position with high accuracy across a wide field of view.
Even a small error can lead to a large problem. Consider, for example, a microscope having an actual magnification of 103 times when the expected magnification, as specified by the manufacturer, is 100 times. The resulting error of 3 percent adds up over large distances across a microscope image. Because of lens imperfections, a subtler problem also occurs—the microscope magnification changes across the image, causing image distortion. To solve this problem, the NIST team designed aperture arrays and calibration processes that worked across large fields of view.
The aperture arrays, which would enable individual researchers to perform calibrations in their own laboratories, could improve by a factor of 10,000 the ability of optical microscopes to accurately locate the position of single molecules and nanoparticles.
Stavis and his colleagues, including first author Craig Copeland of NIST and the Maryland NanoCenter at the University of Maryland, reported their findings in a recently posted article (link is external) in Light: Science & Applications.
“We have identified and solved an underappreciated problem,” said Copeland.
Having calibrated their optical microscope using the arrays, the team reversed the process, using their microscope to identify imperfections in the prototype arrays from the nanofabrication process. “We tested the limits of nanofabrication to control the aperture spacing,” noted co-author Rob Ilic, manager of NIST’s NanoFab. The ease and speed of optical microscopy could facilitate quality control of aperture arrays in a production process.
Finally, the team exploited the inherent stability of the aperture arrays to evaluate whether fluorescent nanoparticles, often used as fixed points of reference in optical microscopy, actually remained fixed to a particular point or if they moved around. The researchers found that while unintentional motions of their optical microscope made views of the nanoparticles blurry, using the aperture array showed that the nanoparticles were not actually moving at atomic scales.

####

For more information, please click here

Contacts:
Ben P. Stein
(link sends e-mail)
(301) 975-2763

Copyright © National Institute of Standards and Technology (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 Links

Paper: Craig R. Copeland, Jon Geist, Craig D. McGray, Vladimir A. Aksyuk, J. Alexander Liddle, B. Robert Ilic and Samuel M. Stavis. Subnanometer localization accuracy in widefield optical microscopy. Light: Science & Applications. Accepted article posted online 16 May 2018. DOI: 10.1038/s41377-018-0031-z (link is external):

Related News Press

News and information

Neutrons unlock the secrets of limoncello May 21st, 2019

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Laboratories

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

2D insulators with ferromagnetism are rare; researchers just identified a new one May 10th, 2019

Self-powered wearable tech May 8th, 2019

Imaging

New Argonne coating could have big implications for lithium batteries May 14th, 2019

Better microring sensors for optical applications May 10th, 2019

Govt.-Legislation/Regulation/Funding/Policy

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New way to beat the heat in electronics: Rice University lab's flexible insulator offers high strength and superior thermal conduction May 16th, 2019

New Argonne coating could have big implications for lithium batteries May 14th, 2019

Possible Futures

Neutrons unlock the secrets of limoncello May 21st, 2019

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Discoveries

Neutrons unlock the secrets of limoncello May 21st, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

Announcements

Neutrons unlock the secrets of limoncello May 21st, 2019

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New surface treatment could improve refrigeration efficiency: A slippery surface for liquids with very low surface tension promotes droplet formation, facilitating heat transfer May 17th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Machine learning speeds modeling of experiments aimed at capturing fusion energy on Earth May 17th, 2019

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

Generating high-quality single photons for quantum computing: New dual-cavity design emits more single photons that can carry quantum information at room temperature May 17th, 2019

New way to beat the heat in electronics: Rice University lab's flexible insulator offers high strength and superior thermal conduction May 16th, 2019

Tools

New Argonne coating could have big implications for lithium batteries May 14th, 2019

Nanoscale thermometers from diamond sparkles: A novel, non-invasive technique that uses quantum light to measure temperature at the nanoscale has been developed May 3rd, 2019

Sculpting Super-Fast Light Pulses: NIST Nanopillars Shape Light Precisely for Practical Applications May 3rd, 2019

Nanometrics Announces Participation in Upcoming Investor Conferences May 3rd, 2019

Research partnerships

Manipulating atoms one at a time with an electron beam: New method could be useful for building quantum sensors and computers May 17th, 2019

New Argonne coating could have big implications for lithium batteries May 14th, 2019

Sculpting Super-Fast Light Pulses: NIST Nanopillars Shape Light Precisely for Practical Applications May 3rd, 2019

Exploring New Ways to Control Thermal Radiation April 29th, 2019

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project