Oxidised metal powder, essentially rust, has been mixed into a polymer to create a coating that could shield military or space electronics from ionising radiation. Developed at North Carolina State University (NC State), it could add extra protection or enable useful weight savings.
Ionising radiation causes significant problems for electronic devices. To protect against this, devices such as satellites incorporate radiation shielding.
The shielding most commonly found in aerospace devices consists of an aluminium box around sensitive technology, providing a good trade-off between weight and the protection.
In the new technique, the powder-polymer mix is incorporated into a common conformal coating and applied to electronics.
Radiation transport calculations reportedly show shielding comparable to a conventional shield. At low energies, the metal oxide powder reduces both gamma radiation to the electronics by a factor of 300 and the neutron radiation damage by 225%.
The coating is less bulky than a shielding box. Researchers said computer simulations showed the worst performance of the oxide coating still absorbed 30% more radiation than a conventional shield of the same weight.
“Our approach can be used to maintain the same level of radiation shielding and reduce the weight by 30% or more, or you could maintain the same weight and improve shielding by 30% or more compared to the most widely used shielding techniques,” said research co-author Rob Hayes, associate professor of nuclear engineering at NC State. “Either way, our approach reduces the volume of space taken up by shielding.”
Metal oxide powder actually offers less shielding than metal powder, Hayes said, but oxides are less toxic and do not pose electromagnetic challenges that could interfere with a device's operation. He said it is also “much less expensive” than the same amount of pure metal.
“This could potentially reduce the need for conventional shielding materials on space-based electronics,” said first author Mike DeVanzo, a former NC State graduate student who works at Lockheed Martin Space.
The team is continuing to test and fine-tune the shielding technique, and is looking for industrial partners to develop it for commercial use.
The research was published in Radiation Physics and Chemistry.
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