Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Drawing a line, with carbon nanotubes --New low-cost, durable carbon nanotube sensors can be etched with mechanical pencils

MIT chemists designed a new type of pencil lead consisting of carbon nanotubes, allowing them to draw carbon nanotube sensors onto sheets of paper.
Photo: Jan Schnorr
MIT chemists designed a new type of pencil lead consisting of carbon nanotubes, allowing them to draw carbon nanotube sensors onto sheets of paper.

Photo: Jan Schnorr

Abstract:
Carbon nanotubes offer a powerful new way to detect harmful gases in the environment. However, the methods typically used to build carbon nanotube sensors are hazardous and not suited for large-scale production.

Drawing a line, with carbon nanotubes --New low-cost, durable carbon nanotube sensors can be etched with mechanical pencils

Cambridge, MA | Posted on October 9th, 2012

A new fabrication method created by MIT chemists as simple as drawing a line on a sheet of paper may overcome that obstacle. MIT postdoc Katherine Mirica has designed a new type of pencil lead in which graphite is replaced with a compressed powder of carbon nanotubes. The lead, which can be used with a regular mechanical pencil, can inscribe sensors on any paper surface.

The sensor, described in the journal Angewandte Chemie, detects minute amounts of ammonia gas, an industrial hazard. Timothy Swager, the John D. MacArthur Professor of Chemistry and leader of the research team, says the sensors could be adapted to detect nearly any type of gas.

"The beauty of this is we can start doing all sorts of chemically specific functionalized materials," Swager says. "We think we can make sensors for almost anything that's volatile."

Other authors of the paper are graduate student Jonathan Weis and postdocs Jan Schnorr and Birgit Esser.

Pencil it in

Carbon nanotubes are sheets of carbon atoms rolled into cylinders that allow electrons to flow without hindrance. Such materials have been shown to be effective sensors for many gases, which bind to the nanotubes and impede electron flow. However, creating these sensors requires dissolving nanotubes in a solvent such as dichlorobenzene, using a process that can be hazardous and unreliable.

Swager and Mirica set out to create a solvent-free fabrication method based on paper. Inspired by pencils on her desk, Mirica had the idea to compress carbon nanotubes into a graphite-like material that could substitute for pencil lead.

To create sensors using their pencil, the researchers draw a line of carbon nanotubes on a sheet of paper imprinted with small electrodes made of gold. They then apply an electrical current and measure the current as it flows through the carbon nanotube strip, which acts as a resistor. If the current is altered, it means gas has bound to the carbon nanotubes.

The researchers tested their device on several different types of paper, and found that the best response came with sensors drawn on smoother papers. They also found that the sensors give consistent results even when the marks aren't uniform.

Two major advantages of the technique are that it is inexpensive and the "pencil lead" is extremely stable, Swager says. "You can't imagine a more stable formulation. The molecules are immobilized," he says.

Sensors for any gas

In this study, the researchers focused on pure carbon nanotubes, but they are now working on tailoring the sensors to detect a wide range of gases. Selectivity can be altered by adding metal atoms to the nanotube walls, or by wrapping polymers or other materials around the tubes.

One gas the researchers are particularly interested in is ethylene, which would be useful for monitoring the ripeness of fruit as it is shipped and stored. The team is also pursuing sensors for sulfur compounds, which might prove helpful for detecting natural gas leaks.

The research was funded by the Army Research Office through MIT's Institute for Soldier Nanotechnologies and a National Institutes of Health fellowship to Mirica.

Written by Anne Trafton, MIT News Office

####

For more information, please click here

Contacts:
Caroline McCall
MIT News Office

T: 617-253-1682

Copyright © MIT

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

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Spider silk: Mother Nature's bio-superlens August 22nd, 2016

Industrial Nanotech, Inc. Provides Shareholder Update August 22nd, 2016

Videos/Movies

Scientists uncover origin of high-temperature superconductivity in copper-oxide compound: Analysis of thousands of samples reveals that the compound becomes superconducting at an unusually high temperature because local electron pairs form a 'superfluid' that flows without resist August 19th, 2016

Argonne discovery yields self-healing diamond-like carbon August 7th, 2016

Diamond-based light sources will lay a foundation for quantum communications of the future: Electrified quantum diamond can become the heart of quantum networks and computers of the future August 7th, 2016

Project to help bring widespread use of micro-robotics August 3rd, 2016

Govt.-Legislation/Regulation/Funding/Policy

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Spider silk: Mother Nature's bio-superlens August 22nd, 2016

A new way to display the 3-D structure of molecules: Metal-organic frameworks provide a new platform for solving the structure of hard-to-study samples August 21st, 2016

Curbing the life-long effects of traumatic brain injury August 19th, 2016

Nanotubes/Buckyballs/Fullerenes

McMaster researchers resolve a problem that has been holding back a technological revolution August 18th, 2016

'Second skin' protects soldiers from biological and chemical agents August 5th, 2016

Carbon nanotube 'stitches' make stronger, lighter composites: Method to reinforce these materials could help make airplane frames lighter, more damage-resistant August 4th, 2016

Easier, faster, cheaper: A full-filling approach to making nanotubes of consistent quality: Approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes July 19th, 2016

Sensors

Down to the wire: ONR researchers and new bacteria August 18th, 2016

'Sniffer plasmons' could detect explosives: Scientists have proposed a graphene-based spaser that can detect even small amounts of various substances, including explosives August 16th, 2016

Perpetual 'ice water': Stable solid-liquid state revealed in nanoparticles: Gallium nanoparticles that are both solid and liquid are stable over a range of 1000 degrees Fahrenheit August 5th, 2016

New metamaterials can change properties with a flick of a light-switch: Material can lead to new optical devices August 3rd, 2016

Discoveries

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Spider silk: Mother Nature's bio-superlens August 22nd, 2016

A new way to display the 3-D structure of molecules: Metal-organic frameworks provide a new platform for solving the structure of hard-to-study samples August 21st, 2016

Announcements

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Spider silk: Mother Nature's bio-superlens August 22nd, 2016

Industrial Nanotech, Inc. Provides Shareholder Update August 22nd, 2016

Military

Nanoparticles that speed blood clotting may someday save lives August 23rd, 2016

Curbing the life-long effects of traumatic brain injury August 19th, 2016

Lab team spins ginger into nanoparticles to heal inflammatory bowel disease August 19th, 2016

Down to the wire: ONR researchers and new bacteria August 18th, 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







Car Brands
Buy website traffic