Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > The quest for the tiny carbon nanotube

Tom Flores
Tom Flores

Abstract:
As he tailors one of the world's finest imaging instruments to tackle one of science's most baffling challenges, Tom Flores feels like he's playing a microscopic game of Where's Waldo.

The quest for the tiny carbon nanotube

Bethlehem, PA | Posted on November 1st, 2011

Flores, a junior majoring in physics, is on a quest for something more elusive—the tiny carbon nanotube.

Carbon nanotubes measure 1 to 5 nanometers in diameter. One nanometer is a billionth of a meter, or between one ten-thousandth and one hundred-thousandth the thickness of a human hair.

With unmatched strength, stiffness and hardness, and length-to-diameter ratios of as much as millions to one, CNTs have potential in medicine, energy and many other applications.

But their infinitesimal size makes it difficult to find and observe CNTs. While Waldo hides behind people, CNTs conceal themselves among bumps, nicks, specks of dust and other imperfections on a microscope slide. They reveal their presence by emitting infrared light when a light source is directed at them.

An ultrathin plane of focus

Flores began studying CNTs last spring with Slava Rotkin, associate professor of physics, and continued last summer in the physics department's Research Experience for Undergraduates program. Funded by the National Science Foundation, the program enables students to do a 10-week paid internship alongside a faculty member.

Lehigh's REU program, with more than two decades of NSF funding, is one of the nation's oldest. In the past five years, an average of 25 to 28 students, roughly one-third from Lehigh, have taken part in the internship.

Flores and two graduate students—Massooma Pirbhai and Tetyana Ignatova—study CNTs with a custom-made NTEGRA-Spectra recently acquired by Rotkin and Richard Vinci, professor of materials science and engineering. The instrument pairs an optical microscope with an atomic-force microscope (AFM), whose needle-like probe scans a surface and records its topographical features.

Flores and his colleagues combine AFM with an optical imaging technique called total internal reflection fluorescence.

"TIRF is a form of photoluminescence," says Flores. "You excite an object so that it gives off light, which provides information about the object and its properties.

"TIRF can excite an object in an extremely thin plane. We study single-walled CNTs, which are 1 nm in diameter. Our plane of focus has to be very thin; if not, we get luminescence from impurities near our sample."

A unique integration of microscopy techniques

Flores uses the AFM probe tip to locate the position of CNTs on a sample.

"We produce an AFM topographical image that shows us where we need to focus. The resolution of that image is limited only by the diameter of the tip. This is much better than you can do with an optics probe.

"Our project is like a game of Where's Waldo. We're trying to find a tiny object in a giant sample. We have to combine information from the AFM about physical characteristics—shape and size—with information supplied by TIRF about how light interacts with the sample."

Only one other research group in the U.S., says Flores, integrates AFM and TIRF in a setup exactly the same as Lehigh's. Combining the two techniques requires resourcefulness. To achieve optimum focus and illumination, Flores and his colleagues have had to modify the sample stage and lenses of the optical microscope.

"Our overall goal is to find and examine CNTs and characterize their properties so that engineers can find applications for them.

"We don't have images of CNTs yet, but we have produced images of polyethylene beads with dyes that emit light at various wavelengths.

"So we know our system is working."

####

For more information, please click here

Contacts:
Kurt Pfitzer

Copyright © Lehigh University

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 News Press

News and information

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Imaging

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Controlled electron pulses November 30th, 2016

Novel silicon etching technique crafts 3-D gradient refractive index micro-optics November 28th, 2016

Scientists shrink electron gun to matchbox size: Terahertz technology has the potential to enable new applications November 25th, 2016

Nanotubes/Buckyballs/Fullerenes

Infrared instrumentation leader secures exclusive use of Vantablack coating December 5th, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Cutting-edge nanotechnologies are breaking into industries November 18th, 2016

Hybrid nanostructures hold hydrogen well: Rice University scientists say boron nitride-graphene hybrid may be right for next-gen green cars October 25th, 2016

Discoveries

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Fast, efficient sperm tails inspire nanobiotechnology December 5th, 2016

Announcements

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Tools

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Controlled electron pulses November 30th, 2016

Scientists shrink electron gun to matchbox size: Terahertz technology has the potential to enable new applications November 25th, 2016

News from Quorum: The Agricultural Research Service of the USDA uses a Quorum Cryo-SEM preparation system for the study of mites, ticks and other soft bodied organisms November 22nd, 2016

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