A new technique for shielding military and space grade electronics from ionizing radiation is underpinned by a surprising secret ingredient: rust.
Developed by a group at North Carolina State University in the US the new technique, which relies on mixing oxidised metal powder – rust – into a polymer, and then incorporating it into a common conformal coating on the relevant electronics is claimed to have a number of advantages of existing techniques.
Ionising radiation can cause significant problems for electronic devices. To protect against this, devices that may be exposed to radiation – such as devices used in spacecraft – incorporate radiation shielding. Weight is a significant factor in designing aerospace technologies, and the shielding most commonly found in aerospace devices consists of putting an aluminium box around any sensitive technologies. This has been viewed as providing the best trade-off between a shield’s weight and the protection it provides.
“Our approach can be used to maintain the same level of radiation shielding and reduce the weight by 30 per cent or more, or you could maintain the same weight and improve shielding by 30 per cent or more – compared to the most widely used shielding techniques,” said Rob Hayes, co-author of a paper on the work and an associate professor of nuclear engineering at NC State. “Either way, our approach reduces the volume of space taken up by shielding.”
Mike DeVanzo, a former graduate student at NC State and first author on the work added that calculations have shown that the inclusion of the metal oxide powder provides 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 per cent.”
DeVanzo added that the technique could reduce the need for conventional shielding materials on space-based electronics.
The researchers are continuing to test and fine-tune their shielding technique for use in various applications.