When Nobukazu Teranishi began tinkering with semiconductors in the University of Tokyo’s undergraduate physics lab, he never dreamed it would land him the world’s most prestigious engineering prize. As he prepares to receive his award at Buckingham Palace next month, the news of the announcement is still sinking in.
“It makes me very happy and proud to have spent 40 years developing digital imaging sensors. There are so many technologies that are indispensable to our everyday lives and I feel very lucky that our work on imaging sensors has been chosen,” he said.
Teranishi is one of four engineers responsible for creating the digital imaging sensors found in digital cameras and smartphones around the world- and above it. His innovation, the pinned photodiode, is the missing puzzle piece linking the first CCD sensors to the tiny CMOS sensors of today.
Finding the missing piece
Photodiodes are semiconductors that, when exposed to light, force electrical current to flow in one direction only, like an electrical one-way valve. Teranishi’s pinned photodiode is far smaller and much more efficient than those found in Tompsett’s original CCD imagers. Its improved performance meant the light-sensitive areas of sensors, called pixels, could be shrunk, packing more light-sensing cells into the same space. The resulting images were higher resolution and much better quality than before.
The PPD became a crucial component in almost all CCD sensors and in the 1990s the technology was incorporated into the new generation of imagers, CMOS sensors.
Since developing the PPD in the 1980s, Teranishi has worked with the Panasonic Corporation developing new image sensors for different application. “Our main goal was the shrink the size of the sensors and cameras, while increasing the number and resolution of pixels,” he said. “We developed different sensors for movie cameras, digital still cameras, endoscopes, automobiles and even games.”
After leaving the corporation, he went on to the University of Hyogo and Shizuoka University, where he is continuing to experiment with new ideas. These include X-ray image sensors to capture the structure of proteins and photon counting sensors, which can detect individual ‘particles’ of light.
Who wants to be an engineer?
Although named as one of the world’s greatest living engineers, Teranishi pointed out that the status of all engineers must be improved. Speaking after winning the 2017 QEPrize, he was keen to put himself forwards as a role model to younger people. While yet to decide a specific project, Teranishi intends to donate his winnings to encouraging high school students into science and engineering.
“Some children want to be sports stars and play soccer or baseball,” he said. “Some want to become singers, and others scientists. Unfortunately, I have not met many children who want to become an engineer. I would like to encourage young people to take an interest in engineering and making things. This is very important to keep and to improve technologies and industrial capabilities.”
With an eye to the future, Teranishi is looking to keep the QEPrize in the family, hoping technologies that help connect generations will win. “In modern countries, the nuclear or two-generation family is common,” he said. “This brings alienation and less aid to both young families and grandparents, as they are not nearby. We need technologies that bring generations closer together.”
“The number of elders who need care is also increasing rapidly,” he added. “Care technologies with personal warmth are required in the future.”