Featured Research

from universities, journals, and other organizations

Engineers fine-tune the sensitivity of nano-chemical sensor

Date:
May 8, 2013
Source:
University of Illinois at Chicago
Summary:
Researchers have discovered a technique for controlling the sensitivity of graphene chemical sensors.

Researchers have discovered a technique for controlling the sensitivity of graphene chemical sensors.

The sensors, made of an insulating base coated with a graphene sheet--a single-atom-thick layer of carbon--are already so sensitive that they can detect an individual molecule of gas. But manipulating the chemical properties of the insulating layer, without altering the graphene layer, may yet improve their ability to detect the most minute concentrations of various gases.

The finding "will open up entirely new possibilities for modulation and control of the chemical sensitivity of these sensors, without compromising the intrinsic electrical and structural properties of graphene," says Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering at the University of Illinois at Chicago, and principal investigator on the study. He and his coworkers at the UIC College of Engineering collaborated with researchers from the Beckman Institute and the Micro and Nanotechnology Laboratory at the University of Illinois at Urbana-Champaign and two institutions in Korea. Their findings are reported in the journal Nano Letters, available online in advance of publication.

Since its discovery nearly 10 years ago, graphene--in sheets, or rolled into nanotubes--has attracted huge scientific interest. Composed of a single layer of carbon atoms, graphene has potential for use in hundreds of high-tech applications. Its 2-D structure, exposing its entire volume, makes it attractive as a highly sensitive gas detector.

Salehi-Khojin's team, and others, earlier found that graphene chemical sensors depended on a structural flaw around a carbon atom for their sensitivity. They set out to show that "pristine" graphene sensors--made of graphene that was perfectly flawless -- wouldn't work. But when they tested these sensors, they found they were still sensitive to trace gas molecules.

"This was a very surprising result," Salehi-Khojin said.

The researchers tested the sensor layer by layer. They found that pristine graphene is insensitive, as they had predicted.

They next set about removing any flaws, or reactive sites called dangling bonds, from the insulating layer. When a pristine insulating layer was tested with pristine graphene, again there was no sensitivity.

"But when dangling bonds were added back onto the insulating layer, we observed a response," said Bijandra Kumar, a post-doctoral research associate at UIC and first author of the Nano Letter study.

"We could now say that graphene itself is insensitive unless it has defects--internal defects on the graphene surface, or external defects on the substrate surface," said UIC graduate student Poya Yasaei.

The finding opens up a new "design space," Salehi-Khojin said. Controlling external defects in the supporting substrates will allow graphene chemFETs to be engineered that may be useful in a wide variety of applications.

K. Min, A. Barati Farimani, D. Estrada, E. Pop, and N.R. Aluru of the University of Illinois at Urbana-Champaign; M.-H. Bae of UIUC and the Korea Research Institute of Standards and Science; and Y.D. Kim and Y.D. Park of Seoul National University also contributed to the study. The study was funded by UIC.


Story Source:

The above story is based on materials provided by University of Illinois at Chicago. The original article was written by Jeanne Galatzer-Levy. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Chicago. "Engineers fine-tune the sensitivity of nano-chemical sensor." ScienceDaily. ScienceDaily, 8 May 2013. <www.sciencedaily.com/releases/2013/05/130508122839.htm>.
University of Illinois at Chicago. (2013, May 8). Engineers fine-tune the sensitivity of nano-chemical sensor. ScienceDaily. Retrieved August 2, 2014 from www.sciencedaily.com/releases/2013/05/130508122839.htm
University of Illinois at Chicago. "Engineers fine-tune the sensitivity of nano-chemical sensor." ScienceDaily. www.sciencedaily.com/releases/2013/05/130508122839.htm (accessed August 2, 2014).

Share This




More Matter & Energy News

Saturday, August 2, 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