Featured Research

from universities, journals, and other organizations

Are electron tweezers possible? Apparently so

Date:
November 10, 2011
Source:
National Institute of Standards and Technology (NIST)
Summary:
A recent paper 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.

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.

Related Articles


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."


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. Vladimir P. Oleshko, James M. Howe. Are electron tweezers possible? Ultramicroscopy, 2011; 111 (11): 1599 DOI: 10.1016/j.ultramic.2011.08.015

Cite This Page:

National Institute of Standards and Technology (NIST). "Are electron tweezers possible? Apparently so." ScienceDaily. ScienceDaily, 10 November 2011. <www.sciencedaily.com/releases/2011/11/111109161305.htm>.
National Institute of Standards and Technology (NIST). (2011, November 10). Are electron tweezers possible? Apparently so. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2011/11/111109161305.htm
National Institute of Standards and Technology (NIST). "Are electron tweezers possible? Apparently so." ScienceDaily. www.sciencedaily.com/releases/2011/11/111109161305.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Inspectors Found Faulty Work Before NYC Blast

Inspectors Found Faulty Work Before NYC Blast

AP (Mar. 27, 2015) An hour before an apparent gas explosion sent flames soaring and debris flying at a Manhattan apartment building, injuring 19 people, utility company inspectors decided the work being done there was faulty. (March 27) Video provided by AP
Powered by NewsLook.com
Facebook Building Plane-Sized Drones For Global Internet

Facebook Building Plane-Sized Drones For Global Internet

Newsy (Mar. 27, 2015) Facebook on Thursday revealed more details about its Internet-connected drone project. The drone is bigger than a 737, but lighter than a car. Video provided by Newsy
Powered by NewsLook.com
Residents Witness Building Explosion, Collapse

Residents Witness Building Explosion, Collapse

AP (Mar. 26, 2015) Witnesses recount the sites and sounds of a massive explosion and subsequent building collapse in the heart of Manhattan&apos;s trendy East Village on Thursday. (March 26) Video provided by AP
Powered by NewsLook.com
Amazon Complains U.S. Is Too Slow To Regulate Drones

Amazon Complains U.S. Is Too Slow To Regulate Drones

Newsy (Mar. 25, 2015) Days after getting approval to test certain commercial drones, Amazon says the Federal Aviation Administration is dragging its feet on the matter. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins