14 DAY TRIAL // A group of investigators from the University of Utah announce the development of advanced, tiny plasma-based transistors, which are capable of working at temperatures of up to 790 degrees Celsius, or 1,454°F. This is more than twice the temperature at which conventional, silicon-based transistors fail.
At 350°C (662°F), silicon transistors simply break down and become unable to carry electricity properly. Silicon carbide circuits were developed to handle this limitation. Such transistors can endure temperatures of up to 550°C (1,022°F) and are currently used for very harsh environments, such as deep oil wells or jet engines. However, for some applications, even silicon carbide circuits are not enough.
The UU team was able to exceed these limitations by developing micro-plasma transistors that can operate in the extreme environment of a nuclear reactor. The new devices are roughly 500 times smaller than the first transistors in this class, which were first developed no more than 5 years ago.
Retaining the ability to operate under extreme temperatures is very important for circuits. Without it, it would be impossible to construct robots capable of working inside a nuclear reactor. Such machines do not currently exist, as the blistering heat melts all their electronics. Developing such robots could make activities such as cleaning up the Fukushima Daiichi power plant in Japan much easier.
In addition, logical circuits made out of plasma-based transistors could enable nuclear installations to withstand most types of emergencies or even extreme scenarios such as nuclear attacks, explains UU professor of electrical and computer engineering Massood Tabib-Azar, quoted by IEEE Spectrum. The expert led the new investigation with postdoctoral researcher Pradeep Pai.
Details of the innovative transistors are published in the March 20 online issue of the respected scientific journal IEEE Electron Device Letters. The most important thing separating the new devices from their predecessors is the fact that their semiconductor channels are filled with plasma, a type of partially-ionized gas.
The devices can operate at just 50 volts – a power level six times lower than what is needed for current generations of plasma-based transistors – and are between 1 to 6 microns in length. Previous models are up to 500 micrometers long, the team explains. The next step is to create logical circuits with these transistors and then test them inside an experimental nuclear reactor at UU.
In addition to potential applications inside nuclear facilities, the new circuits could also be used to generate X-rays, such as in mobile devices. Having the ability to create an X-ray scan in the battlefield using nothing more than a smartphone could mean the difference between life and death for many soldiers.