Silicon carbide technology to take electronics to the extreme
By Darren Quick
September 20, 2010
New technology using silicon carbide electronics could enable radio transmitters that can withstand temperatures of up to 900 degrees Celsius (1,652 F). No, it’s not being developed so listeners can enjoy their favorite breakfast DJ in a worst-case global warming scenario. Rather the team behind the research envisions devices that could be dropped into the depths of the earth to provide early warning of a volcanic eruption or to provide real time data from the inside of a jet engine or nuclear power plant.
Building reliable components that will continue to work under extreme conditions has been an on-going challenge for electronic engineers. To ‘go where no technology has gone before’ and unlock the secrets of some of the world’s harshest environments, a team from Newcastle University in England is using a compound of silicon and carbon called silicon carbide (SiC), or carborundum, which is already used in high temperature/high voltage semiconductor electronics.
Strong bondsBecause of its unique molecular structure – which is more stable than silicon – SiC also has a high radiation tolerance opening up possibilities for its use in the nuclear industry. The secret of SiC is the much stronger bonds between the silicon and carbon atoms, which also require more energy to release electrons for electrical conduction. However, this also makes it more difficult to manufacture into components.
The team has successfully managed to develop the necessary components and is now working to integrate them into a device about the size of an iPhone that could be used in a variety of locations such as power plants, aircraft engines and even volcanoes.
Dr Alton Horsfall, who leads the SiC work alongside Professor Nick Wright, explains: "At the moment we have no way of accurately monitoring the situation inside a volcano and in fact most data collection actually goes on post-eruption. With an estimated 500 million people living in the shadow of a volcano this is clearly not ideal.
"We still have some way to go but using silicon carbide technology we hope to develop a wireless communication system that could accurately collect and transmit chemical data from the very depths of a volcano," Horsfall said.
Volcanic monitoring is just one of the strands of research being carried out at the Centre for Extreme Environment Technology.
Underwater and the undergroundWith expertise in underwater communications, Professor Bayan Sharif, Jeff Neasham and Dr Charalampos Tsimenidis have developed a micro Remotely-Operated Vehicle that can be used to feed back environmental data about our coastlines. The team is also working on through metal communications which involves transmitting a signal through almost 10cm (3.9-in) of steel and wireless sensor networks.
"If someone sets off a bomb on the underground, for example, this will still sit on the wall and tell you what’s going on," says Dr Horsfall. “If a dirty bomb has gone off you want to know what’s happened before you send anyone in."
Professor Nick Wright, pro-vice chancellor for innovation and research at Newcastle University, added: "The situations we are planning to use our technology in means it’s not enough for the electronics to simply withstand extremes of temperature, pressure or radiation – they have to continue operating absolutely accurately and reliably.
"Increasingly mankind is spreading out into harsher and more extreme environments as our population grows and we explore new areas for possible sources of energy and food in order to sustain it. But with this comes new challenges and this is why research into extreme technologies is becoming ever more important."