Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Are electron tweezers possible? Apparently so

Abstract:
Not to pick up electrons, but tweezers made of electrons. A recent paper* by researchers from the National Institute of Standards and Technology (NIST) and the University of Virginia (UVA) demonstrates that the beams produced by modern electron microscopes can be used not just to look at nanoscale objects, but to move them around, position them and perhaps even assemble them.

Are electron tweezers possible? Apparently so

Gaithersburg, MD | Posted on November 9th, 2011

Essentially, they say, the tool is an electron version of the laser "optical tweezers" that have become a standard tool in biology, physics and chemistry for manipulating tiny particles. Except that electron beams could offer a thousand-fold improvement in sensitivity and resolution.

Optical tweezers were first described in 1986 by a research team at Bell Labs. The general idea is that under the right conditions, a tightly focused laser beam will exert a small but useful force on tiny particles. Not pushing them away, which you might expect, but rather drawing them towards the center of the beam. Biochemists, for example, routinely use the effect to manipulate individual cells or liposomes under a microscope.

If you just consider the physics, says NIST metallurgist Vladimir Oleshko, you might expect that a beam of focused electrons—such as that created by a transmission electron microscope (TEM)—could do the same thing. However that's never been seen, in part because electrons are much fussier to work with. They can't penetrate far through air, for example, so electron microscopes use vacuum chambers to hold specimens.

So Oleshko and his colleague, UVA materials scientist James Howe, were surprised when, in the course of another experiment, they found themselves watching an electron tweezer at work. They were using an electron microscope to study, in detail, what happens when a metal alloy melts or freezes. They were observing a small particle—a few hundred microns wide—of an aluminum-silicon alloy held just at a transition point where it was partially molten, a liquid shell surrounding a core of still solid metal. In such a small sample, the electron beam can excite plasmons, a kind of quantized wave in the alloy's electrons, that reveals a lot about what happens at the liquid-solid boundary of a crystallizing metal. "Scientifically, it's interesting to see how the electrons behave," says Howe, "but from a technological point of view, you can make better metals if you understand, in detail, how they go from liquid to solid."

"This effect of electron tweezers was unexpected because the general purpose of this experiment was to study melting and crystallization," Oleshko explains. "We can generate this sphere inside the liquid shell easily; you can tell from the image that it's still crystalline. But we saw that when we move or tilt the beam—or move the microscope stage under the beam—the solid particle follows it, like it was glued to the beam."

Potentially, Oleshko says, electron tweezers could be a versatile and valuable tool, adding very fine manipulation to wide and growing lists of uses for electron microscopy in materials science.** "Of course, this is challenging because it requires a vacuum," he says, "but electron probes can be very fine, three orders of magnitude smaller than photon beams—close to the size of single atoms. We could manipulate very small quantities, even single atoms, in a very precise way."

* V.P. Oleshko and J.M. Howe. Are electron tweezers possible? Ultramicroscopy (2011) doi:10.1016/j.ultramic.2011.08.015.

####

For more information, please click here

Contacts:
Michael Baum

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

See, for example, the Jan. 19, 2011, Tech Beat story "NIST Puts a New Twist on the Electron Beam" at:

Related News Press

News and information

Promising Step Taken in Iran towards Treatment of Spinal Cord Injury August 3rd, 2015

Diagnosis of Salmonella Bacterium-Caused Food Poisoning by Biosensors August 3rd, 2015

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Kalam: versatility personified August 1st, 2015

Laboratories

Springer and Tsinghua University Press present the second Nano Research Award: Paul Alivisatos of the University of California Berkeley receives the honor for outstanding contributions in nanoscience July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

New computer model could explain how simple molecules took first step toward life: Two Brookhaven researchers developed theoretical model to explain the origins of self-replicating molecules July 28th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Kalam: versatility personified August 1st, 2015

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Theoretical Physicists at Freie Universität Berlin Develop New Insights into Interface between Classical and Quantum Worlds July 31st, 2015

Announcements

Promising Step Taken in Iran towards Treatment of Spinal Cord Injury August 3rd, 2015

Diagnosis of Salmonella Bacterium-Caused Food Poisoning by Biosensors August 3rd, 2015

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Advances and Applications in Biosensing, Sensor Power, and Sensor R&D to be Covered at Sensors Global Summit August 1st, 2015

Tools

Thin films offer promise for ferroelectric devices: Researchers at Tokyo Institute of Technology demystify the ferroelectric properties observed in hafnium-oxide-based thin films, revealing a potentially useful device material August 3rd, 2015

Heating and cooling with light leads to ultrafast DNA diagnostics July 31st, 2015

Take a trip through the brain July 30th, 2015

Publication on Atomic Force Microscopy based nanoscale IR Spectroscopy (AFM-IR) persists as a 2015 top downloaded paper July 29th, 2015

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