Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Light touch keeps a grip on delicate nanoparticles

NIST researchers' new approach to trapping nanoparticles uses a control and feedback system that nudges them only when needed, lowering the average intensity of the beam and increasing the lifetime of the nanoparticles while reducing their tendency to wander. On the left, 100-nanometer gold nanoparticles quickly escape from a static trap while gold nanoparticles trapped using the NIST method remained strongly confined.

Credit: NIST
NIST researchers' new approach to trapping nanoparticles uses a control and feedback system that nudges them only when needed, lowering the average intensity of the beam and increasing the lifetime of the nanoparticles while reducing their tendency to wander. On the left, 100-nanometer gold nanoparticles quickly escape from a static trap while gold nanoparticles trapped using the NIST method remained strongly confined.

Credit: NIST

Abstract:
Using a refined technique for trapping and manipulating nanoparticles, researchers at the National Institute of Standards and Technology (NIST) have extended the trapped particles' useful life more than tenfold.* This new approach, which one researcher likens to "attracting moths," promises to give experimenters the trapping time they need to build nanoscale structures and may open the way to working with nanoparticles inside biological cells without damaging the cells with intense laser light.

Light touch keeps a grip on delicate nanoparticles

Gaithersburg, MD | Posted on May 4th, 2012

Scientists routinely trap and move nanoparticles in a solution with "optical tweezers"—a laser focused to a very small point. The tiny dot of laser light creates a strong electric field, or potential well, that attracts particles to the center of the beam. Although the particles are attracted into the field, the molecules of the fluid they are suspended in tend to push them out of the well. This effect only gets worse as particle size decreases because the laser's influence over a particle's movement gets weaker as the particle gets smaller. One can always turn up the power of the laser to generate a stronger electric field, but doing that can fry the nanoparticles too quickly to do anything meaningful with them—if it can hold them at all.

NIST researchers' new approach uses a control and feedback system that nudges the nanoparticle only when needed, lowering the average intensity of the beam and increasing the lifetime of the nanoparticle while reducing its tendency to wander. According to Thomas LeBrun, they do this by turning off the laser when the nanoparticle reaches the center and by constantly tracking the particle and moving the tweezers as the particle moves.

"You can think of it like attracting moths in the dark with a flashlight," says LeBrun. "A moth is naturally attracted to the flashlight beam and will follow it even as the moth flutters around apparently at random. We follow the fluttering particle with our flashlight beam as the particle is pushed around by the neighboring molecules in the fluid. We make the light brighter when it gets too far off course, and we turn the light off when it is where we want it to be. This lets us maximize the time that the nanoparticle is under our control while minimizing the time that the beam is on, increasing the particle's lifetime in the trap."

Using this method at constant average beam power, 100-nanometer gold particles remained trapped 26 times longer than had been seen in previous experiments. Silica particles 350 nanometers in diameter lasted 22 times longer, but with the average beam power reduced by 33 percent. LeBrun says that their approach should be able to be combined with other techniques to trap and hold even smaller nanoparticles for extended periods without damaging them.

"We're more than an order of magnitude ahead of where we were before," says LeBrun. "We now hope to begin building complex nanoscale devices and testing nanoparticles as sensors and drugs in living cells."

####

For more information, please click here

Contacts:
Mark Esser

301-975-8735

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

* A. Balijepalli, J. Gorman, S. Gupta and T. LeBrun. Significantly Improved Trapping Lifetime of Nanoparticles in an Optical Trap using Feedback Control. Nano Letters. April 10, 2012. Available online:

Related News Press

News and information

University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014

Nature inspires a greener way to make colorful plastics July 30th, 2014

Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials July 30th, 2014

FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research July 30th, 2014

Laboratories

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

NIST shows ultrasonically propelled nanorods spin dizzyingly fast July 22nd, 2014

Sono-Tek Corporation Announces New Clean Room Rated Laboratory Facility in China July 18th, 2014

Fundamental Chemistry Findings Could Help Extend Moore’s Law: A Berkeley Lab-Intel collaboration outlines the chemistry of photoresist, enabling smaller features for future generations of microprocessors July 15th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Nature inspires a greener way to make colorful plastics July 30th, 2014

Tough foam from tiny sheets: Rice University lab uses atom-thick materials to make ultralight foam July 29th, 2014

A new way to make microstructured surfaces: Method can produce strong, lightweight materials with specific surface properties July 29th, 2014

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Nanomedicine

Zenosense, Inc. July 29th, 2014

Optimum inertial design for self-propulsion: A new study investigates the effects of small but finite inertia on the propulsion of micro and nano-scale swimming machines July 29th, 2014

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

New imaging agent provides better picture of the gut July 25th, 2014

Sensors

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Compact Vibration Harvester Power Supply with Highest Efficiency Opens Door to “Fix-and-Forget” Sensor Nodes July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

Discoveries

Flexible Metamaterial Absorbers July 29th, 2014

Zenosense, Inc. July 29th, 2014

Optimum inertial design for self-propulsion: A new study investigates the effects of small but finite inertia on the propulsion of micro and nano-scale swimming machines July 29th, 2014

A new way to make microstructured surfaces: Method can produce strong, lightweight materials with specific surface properties July 29th, 2014

Announcements

University of Manchester selects Anasys AFM-IR for coatings and corrosion research July 30th, 2014

Nature inspires a greener way to make colorful plastics July 30th, 2014

Analytical solutions from Malvern Instruments support University of Wisconsin-Milwaukee researchers in understanding environmental effects of nanomaterials July 30th, 2014

FEI Unveils New Solutions for Faster Time-to-Analysis in Metals Research July 30th, 2014

Photonics/Optics/Lasers

Terabyte Photonic Dataset Sale July 30th, 2014

NUS scientists use low cost technique to improve properties and functions of nanomaterials: By 'drawing' micropatterns on nanomaterials using a focused laser beam, scientists could modify properties of nanomaterials for effective applications in photonic and optoelectric applicat July 22nd, 2014

Carbyne morphs when stretched: Rice University calculations show carbon-atom chain would go metal to semiconductor July 21st, 2014

Tiny laser sensor heightens bomb detection sensitivity July 19th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE