Featured Research

from universities, journals, and other organizations

Nanofluidic 'multi-tool' separates and sizes nanoparticles

Date:
August 6, 2010
Source:
National Institute of Standards and Technology (NIST)
Summary:
Researchers have engineered a nanoscale fluidic device that functions as a miniature "multi-tool" for working with nanoparticles-objects whose dimensions are measured in nanometers, or billionths of a meter.

A 3-D nanofluidic "staircase" channel with many depths was used to separate and measure a mixture of different-sized fluorescent nanoparticles. Larger (brighter) and smaller (dimmer) particles were forced toward the shallow side of the channel (fluorescence micrograph on left). The particles stopped at the "steps" of the staircase with depths that matched their sizes.
Credit: S.M. Stavis, NIST

A wrench or a screwdriver of a single size is useful for some jobs, but for a more complicated project, you need a set of tools of different sizes. Following this guiding principle, researchers at the National Institute of Standards and Technology (NIST) have engineered a nanoscale fluidic device that functions as a miniature "multi-tool" for working with nanoparticles -- objects whose dimensions are measured in nanometers, or billionths of a meter.

First introduced in March 2009 (see "NIST-Cornell Team Builds World's First Nanofluidic Device with Complex 3-D Surfaces," the device consists of a chamber with a cascading "staircase" of 30 nanofluidic channels ranging in depth from about 80 nanometers at the top to about 620 nanometers (slightly smaller than an average bacterium) at the bottom. Each of the many "steps" of the staircase provides another "tool" of a different size to manipulate nanoparticles in a method that is similar to how a coin sorter separates nickels, dimes and quarters.

In a new article in the journal Lab on a Chip, the NIST research team demonstrates that the device can successfully perform the first of a planned suite of nanoscale tasks -- separating and measuring a mixture of spherical nanoparticles of different sizes (ranging from about 80 to 250 nanometers in diameter) dispersed in a solution. The researchers used electrophoresis -- the method of moving charged particles through a solution by forcing them forward with an applied electric field -- to drive the nanoparticles from the deep end of the chamber across the device into the progressively shallower channels. The nanoparticles were labeled with fluorescent dye so that their movements could be tracked with a microscope.

As expected, the larger particles stopped when they reached the steps of the staircase with depths that matched their diameters of around 220 nanometers. The smaller particles moved on until they, too, were restricted from moving into shallower channels at depths of around 110 nanometers. Because the particles were visible as fluorescent points of light, the position in the chamber where each individual particle was stopped could be mapped to the corresponding channel depth. This allowed the researchers to measure the distribution of nanoparticle sizes and validate the usefulness of the device as both a separation tool and reference material. Integrated into a microchip, the device could enable the sorting of complex nanoparticle mixtures, without observation, for subsequent application. This approach could prove to be faster and more economical than conventional methods of nanoparticle sample preparation and characterization.

The NIST team plans to engineer nanofluidic devices optimized for different nanoparticle sorting applications. These devices could be fabricated with tailored resolution (by increasing or decreasing the step size of the channels), over a particular range of particle sizes (by increasing or decreasing the maximum and minimum channel depths), and for select materials (by conforming the surface chemistry of the channels to optimize interaction with a specific substance). The researchers are also interested in determining if their technique could be used to separate mixtures of nanoparticles with similar sizes but different shapes -- for example, mixtures of tubes and spheres.


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. S.M. Stavis, J. Geist and M. Gaitan. Separation and metrology of nanoparticles by nanofluidic size exclusion. Lab on a Chip, August 2010

Cite This Page:

National Institute of Standards and Technology (NIST). "Nanofluidic 'multi-tool' separates and sizes nanoparticles." ScienceDaily. ScienceDaily, 6 August 2010. <www.sciencedaily.com/releases/2010/08/100804110214.htm>.
National Institute of Standards and Technology (NIST). (2010, August 6). Nanofluidic 'multi-tool' separates and sizes nanoparticles. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2010/08/100804110214.htm
National Institute of Standards and Technology (NIST). "Nanofluidic 'multi-tool' separates and sizes nanoparticles." ScienceDaily. www.sciencedaily.com/releases/2010/08/100804110214.htm (accessed August 1, 2014).

Share This




More Matter & Energy News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Tesla, Panasonic Ink Deal To Make Huge Battery 'Gigafactory'

Newsy (July 31, 2014) The deal will help build a massive battery factory that Tesla says will produce 500,000 lithium batteries by 2020. Video provided by Newsy
Powered by NewsLook.com
Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Smoked: 2015 Ducati Diavel Vs 2014 Chevy Corvette Stingray Drag Race

Cycle World (July 30, 2014) The Bonnier Motorcycle Group presents Smoked; a three part video series. In this episode the 2015 Ducati Diavel takes on the 2014 Chevy Corvette Stingray Video provided by Cycle World
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:
from the past week

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