Sumio Iijima (1939-) is a physicist currently working at NEC in Japan. He is best known as for his discovery of carbon nanotubes in 1991.
In his youth he loved nature, and spent much of his time exploring it. After graduating from the University of Electro-Communications in Tokyo, he started research with electron microscopes at Tohoku University in Sendai. He found that he was very well suited for this type of research, and completed his Masters, and then PhD in solid state physics in 1968.
In the 70s and early 80s he worked as a Research Associate at Arizona State University. There he developed a new electron microscope that had the ability to view the structure of materials at the atomic level. In 1977 he was able to view individual tungsten atoms, which had been a long-term goal in electron microscopy, then finally realized. This type of novel research became his specialty.
Returning to Japan in 1982, he devoted his time mostly to research in ultrafine particles at the Research Development Corporation of Japan. In 1987 he began work at NEC, as they had a mutual interest in creating a new high-resolution electron microscope that could operate in an extremely high vacuum. It was in 1991, while working at NEC that he discovered carbon nanotubes, which are very useful in research of electronics, optics, and many other applications.
Iijima has been a professor and visiting lecturer at Meijo University since 1999. He is also the director of the Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology. He has received numerous honors and awards for his work in physics.