Tiny sensor can detect radiation far faster than can existing technology

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In a move that could have huge implications for national security, researchers have created a very sensitive and tiny detector that is capable of detecting radiation from various sources at room temperature. The detector is eight to nine orders of magnitude –100 million to as high as 1 billion — times faster than the existing technology, and a Texas A&M University at Galveston professor is a key player in the discovery.

Luke Nyakiti, an assistant professor in Texas A&M University-Galveston’s department of materials science and engineering, is part of the research team that has had its work published in the current issue of Nature Nanotechnology.

Nyakiti and colleagues from the University of Maryland, the University of Massachusetts, the U.S. Naval Research Laboratory and Monash University in Australia fabricated the tiny photothermoelectric detector following successful growth of graphene at the Naval Research Laboratory in Washington, D.C. The project was funded by the office of Naval Research and the National Science Foundation.

The team’s goal was to utilize the exceptional electronic carrier properties of graphene to create a photo detector device that could detect radiation at room temperature with the fastest response, which previously has been extremely difficult to do. The researchers used a two-dimensional material called graphene that is made of carbon atoms that are arranged in a honeycomb-like geometrical structure (the diameter of a human hair is 300,000 times thicker than a two-dimensional sheet of graphene).

Graphene was chosen because it conducts electricity with ease, it is nearly transparent, and it is remarkably strong (100 times stronger than steel).  Also, it is very sensitive to energy absorbance.

“The problem before is that there has always been a ‘slow response’ when it came to detecting radiation in the terahertz frequency range, especially at room temperature, and the technology that currently exists operated at very cold temperatures, subsequently requiring  supportive electronic systems that adds to the cost,” Nyakiti explains.

He says the benefit of using this detector is that its signals do not pose a health hazard to the people using it. Also, besides the extremely high sensing speeds reported by the device, the team anticipates further improvements in sensing ability.

“We are very excited that our detector system provides a unique answer to fast, subtle detection capabilities that are a million to a billion times faster in its detection capability, without posing short-term or long term health hazards to those who are operating it,” Nyakiti  reports .

“It was indeed an exciting time for all of us when this happened.  Because it is much more effective in detecting radiation, the device could be very promising for homeland security purposes.  It also might have applications in mobile devices, medical imaging and other uses.

“This has the potential to open up other device possibilities in medical applications. This is a huge first step.”

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