Smartphone components work beautifully at nearly absolute zero
Transistors are electronic components that act as switches to control current. Their performance is affected by temperature, so specially designed versions are used in super-cold conditions. They are costly and difficult to obtain, however, and complicated circuitry or additional equipment is often needed as well.
Amine Rhouni from the Institute of Research into the Fundamental Laws of the Universe in Gif-Sur-Yvette, France, and his team wanted to see if off-the-shelf transistors could be used instead. If so, it would make research at these temperatures dramatically easier.
The team is developing the next generation of infrared cameras for use in outer space. For maximum sensitivity, they need to operate at the lowest temperatures we can achieve – just above -273°C. And the electronics they bolt on to read their sensors need to hold up as well.
Theory predicted that ordinary transistors would work at such temperatures, but testing them was a different matter. It took three days to cool down their equipment to the target temperature, and they had to use a special set-up to stabilise it – preventing current in the transistors from heating them up, for example.
The tests confirmed that the transistors stood up well to the extreme conditions. Malik Mansour at the University of Paris-Saclay in Saint-Aubin, France is impressed. “It’s difficult to make measurements at such low temperatures,” he says.
Mansour thinks that the results could also be relevant to medical imaging, opening up the possibility of achieving more detailed pictures with supercooled instruments. The whole idea is expensive and complicated at present, but he thinks that it could become feasible in the future. “Cryotechnology will be improved,” he says.
Researchers developing quantum computers have also expressed interest in the results. Rhouni’s team, however, is focused on using the technology on the Spica mission, slated to launch in the late 2020s, to investigate the coldest regions of the universe. During the Herschel mission 15 years ago, they discovered that these star-forming regions are dominated by filaments of gas and dust. Now they want to investigate the role of the filaments using specialised detectors and explain their shape. “We will need to describe their magnetic field,” says Vincent Reveret, a member of the team. “It has never been done before.”
Image credit: Robert Riley/FOAP/Getty