NASA Experiments With Nano-Sized SensorsBy: Sean Patterson - December 6, 2012
NASA is now working with a special material to develop nano-scale sensors that can detect trace elements in Earth’s upper atmosphere and find structural flaws in spacecraft.
The material, called graphene, is just one atom thick and is composed of carbon atoms. It is 200 times as strong as steel, and is stable at extreme temperatures.
“The cool thing about graphene is its properties,” said Jeff Stewart, the acting assistant chief for technology in the Mechanical Systems Division of NASA’s Goddard Space Flight Center. “It offers a plethora of possibilities. Frankly, we’re just getting started.”
Stewart and his colleagues have developed a process to manufacture relatively large, high-quality samples of graphene. Using the material, the researchers are developing a miniature, low-mass, low-power detector that can measure the amount of atomic oxygen in the upper atmosphere. Graphene oxidizes when it absorbs atomic oxygen, creating a change in electrical resistance that can be measured. Such a device will be able to reveal the density of atomic oxygen at such heights, revealing its role in creating atmospheric drag.
“We still don’t know the impact of atomic elements on spacecraft in creating a drag force,” said Fred Herrero, a retired Goddard researcher still working in an emeritus capacity. “We don’t know how much momentum is transferred between the atom and the spacecraft. This is important because engineers need to understand the impact to estimate the lifetime of a spacecraft and how long it will take before the spacecraft reenters Earth’s atmosphere.”
NASA researchers now plan to fabricate and test the first generation of graphene-based chemical sensors by the end of the fiscal year.
(Image courtesy NASA/Pat Izzo)