Navigation Links
Engineers fine-tune the sensitivity of nano-chemical sensor
Date:5/8/2013

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 Letter, 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 flawlesswouldn'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.


'/>"/>

Contact: Jeanne Galatzer-Levy
jgala@uic.edu
312-996-1583
University of Illinois at Chicago
Source:Eurekalert

Related biology technology :

1. Stanford engineers use nanophotonics to reshape on-chip computer data transmission
2. Arizona State University engineers aim to improve performance of technology in extreme environments
3. Stanford engineers weld nanowires with light
4. Straintronics: Engineers create piezoelectric graphene
5. Cloak of invisibility: Engineers use plasmonics to create an invisible photodetector
6. Stanford engineers perfecting carbon nanotubes for highly energy-efficient computing
7. Engineers achieve longstanding goal of stable nanocrystalline metals
8. UCLA engineers develop new energy-efficient computer memory using magnetic materials
9. UT Arlington engineers working to prevent heat buildup within 3D integrated circuits
10. Cornell bioengineers discover the natural switch that controls spread of breast cancer cells
11. Forget about leprechauns, engineers are catching rainbows
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... Raleigh, NC (PRWEB) , ... June 27, 2016 ... ... have just published their findings on what they believe could be a new ... summary of the new research. Click here to read it now. ...
(Date:6/27/2016)... June 27, 2016   Ginkgo Bioworks , a ... engineering, was today awarded as one of the ... the world,s most innovative companies. Ginkgo Bioworks is ... the real world in the nutrition, health and ... directly with customers including Fortune 500 companies to ...
(Date:6/23/2016)... ... 2016 , ... Mosio, a leader in clinical research patient ... and Retention Tips.” Partnering with experienced clinical research professionals, Mosio revisits the hurdle ... and strategies for clinical researchers. , “The landscape of how patients receive and ...
(Date:6/23/2016)... , June 23, 2016 Houston ... with the Cy-Fair Sports Association to serve as ... the agreement, Houston Methodist Willowbrook will provide sponsorship ... and connectivity with association coaches, volunteers, athletes and ... with the Cy-Fair Sports Association and to bring ...
Breaking Biology Technology:
(Date:5/16/2016)... --  EyeLock LLC , a market leader of iris-based ... IoT Center of Excellence in Austin, Texas ... embedded iris biometric applications. EyeLock,s iris authentication ... with unmatched biometric accuracy, making it the most proven ... platform uses video technology to deliver a fast and ...
(Date:4/28/2016)... , April 28, 2016 Infosys ... (NYSE: INFY ), and Samsung SDS, a global ... that will provide end customers with a more secure, fast ...      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ) , ... but it also plays a fundamental part in enabling and ...
(Date:4/19/2016)... UAE, April 20, 2016 The ... as a compact web-based "all-in-one" system solution for all ... fingerprint reader or the door interface with integration authorization ... access control systems. The minimal dimensions of the access ... into the building installations offer considerable freedom of design ...
Breaking Biology News(10 mins):