ɫɫ��

Sumio Iijima, Professor at Meijo University was conferred an Honorary Doctorate by Aalto University 10 October 2014.

Thousands of articles are published on carbon nanotubes every year. Material and energy technology, electronics and design are all on the brink of revolution, thanks to carbon nanotubes’ remarkable semiconducting properties, strength and flexibility.

– In the 1990s carbon nanotubes were completely new. Although there were microscopic images of similar structures, there was no evidence of their atomic structure and electron diffraction patterns. I was the first to come up with scientific proof of their existence, Professor Iijima recounts his pioneering work.

Theoretical physicists and experimentalists have worked on carbon nanotubes for over 20 years now. Mass production and commercial applications – bendable and foldable screens and new solar cell technology for instance – are not far from reality.

– As an inventor, I’m greatly looking forward to the success of applications of carbon nanotubes, especially here in Aalto University by Professor Esko Kauppinen. Experiments on them must work on a much larger scale than academic research: only this way we can convince industry of their commercial potential. Cutting costs in producing carbon nanotubes is still an issue, Iijima notes.

Carbon nanotubes: a painstaking “but serendipitous” discovery

Iijima considers himself an experimentalist. For his doctoral studies he found his niche in atomic physics and microscopy. In 1970 he left for USA and Arizona State University for post doc research in electron microscopy. In returning to Japan in the 1980s he studied different kinds of carbon nanostructures, and this line of work saw the discovery of spherical carbon molecules, C60 fullerenes, in 1985. 

In 1990, chemistry Nobel laureate Harry Kroto, who was one of the discoverers of C60 fullerenes, pursued Iijima to fabricate fullerenes and find out how individual carbon atoms form into spherical molecules with his techniques.

– I extended my microscopy technique and started looking at different kinds of carbon nanomaterials. I already had good-quality images of the spherical, onion-layered structure of fullerenes from ten years back, but now, besides the onion, I also found elongated needle-like structures, Iijima explains his game-changing observation.

The “needles” turned out to be single-layered rolls of carbon atom lattices – carbon nanotubes. Iijima published his ground-breaking work in Nature in 1991. Carbon nanotubes soon attracted physicists, chemists and computer scientists all over the world to repeat Iijima’s results, to develop their own fabrication techniques and to understand the scope of the tube’s properties.

– Carbon nanotubes are ideal for computational modelling: they are such small systems that it is possible to include all the atomic coordinates in the model and estimate their electrical, optical or mechanical properties.

Iijima says that theoreticians jumped on carbon nanotubes, and peculiarly, tables turned in the marching order of theory and experimentation.

– Usually experimental scientists have to find proof for theoreticians’ models and predictions, but this time it was the other way around: the new material came first, and theoreticians were those who followed, Iijima laughs.

Although the discovery is unanimously put into Iijima’s name, he calls for historical awareness in marvelling scientific achievements.

– Researchers can’t do anything by themselves. Every breakthrough has its own history – all the work that has come before – and it makes yours possible.

”The NanoMaterials Group in Aalto University make the best carbon nanotubes”

Universities, research centres and companies all over the world have their eye on Aalto University Department of Applied Physics Professor Esko Kauppinen’s work. Professor Iijima has visited Finland often and has particularly followed the research of Professor Kauppinen’s NanoMaterials Group.

– Kauppinen develops great technology for producing extremely high-quality carbon nanotubes for industrial production. For electronic devices to work properly and stably, you can’t use second grade material. Kauppinen is very close to providing supreme carbon nanotubes for commercial applications.