Goggle-type sensor using carbon nanotube film — Enabling non-destructive inspection that sees through objects while viewing them directly

Q1. What inspired you to become a researcher?

A1. I was drawn to the broad range of subjects it covers.

I was completely devoted to baseball in high school-I spent far more time swinging a bat than holding a pencil. What first made me think about my future was the Tokyo Institute of Technology (now the Institute of Science Tokyo), which was located near my high school. I was good at math and science, so I decided to aim for it.

I chose the Department of Electrical and Electronic Engineering because, among the programs available, I was drawn to the wide range of research subjects covered-from things too small to see with the naked eye, such as atoms, to large-scale infrastructure that drives society.

After entering university, I truly enjoyed the freedom to choose my own courses and the time I spent with friends. When I thought that leaving after a bachelor's or master's degree would be a waste, and wondered how I could stay in academia longer, I began to see the path of a doctoral program-and beyond that, a career as a researcher.

Q2. What research are you currently working on?

A2. Merging the experience of skilled technicians with new technology.

I am developing sensors that use a material called carbon nanotubes (CNTs), which can detect infrared and terahertz radiation invisible to the human eye, enabling images to be captured by "seeing through" the inside of objects. I believe that making it possible to check for internal deterioration or damage without destroying the target object will be useful for inspecting social infrastructure such as power lines and gas pipes, as well as for quality control in factories.

I am currently working on developing goggles that use CNT sensors to allow the wearer to see through the inside of an object while simultaneously viewing it themselves. Because the CNT sensor film is made from a liquid as black as ink, attaching it to a goggle as-is would completely block the view. I succeeded in creating a film that is transparent in the visible light range, by selecting only CNTs of specific shapes and types from a mixed batch. Furthermore, by placing "metallic-type" CNTs, which are good at collecting light, next to "semiconducting-type" CNTs, which excel at converting light into electrical signals, I was able to make the film both transmit visible light and effectively absorb infrared and terahertz radiation.

Going forward, I would like to miniaturize and package the circuits that convert data into images while also improving environmental durability and resolution, with an eye toward practical application. My goal is to realize a new method of non-destructive inspection by merging the experience of skilled inspection technicians who are adept at visual assessment with the latest sensing technology.

Q3. A message for those aspiring to become researchers

A3. If you can get totally absorbed in something, research is for you.

Becoming a researcher is not a narrow gate open only to a select few. I myself did nothing but play baseball until I entered university. But the experience of getting completely absorbed in something and continuously asking "How can I get better at this?" carries over directly into research. Whether it is music or sports, if you have something you can truly dedicate yourself to, I believe you already have what it takes to be a researcher.

I first encountered CNTs when I was assigned to a research lab in my fourth year as an undergraduate. At the time, the potential of this material for use in sensors had only just been discovered, and applied research had barely begun. Even as a student, I was lucky enough to stumble into an unexplored field where the work I did could lead directly to new results.

When choosing a research field, I recommend looking not only at what is currently in vogue, but also at the professors themselves. Fields with many professors who do their research with real vitality naturally become lively places. If you find a professor whose eyes light up when they talk about their own work as an aside during a lecture, that field is almost certainly full of inspiration for students too. (Text: Yoshihiro Hatabe)