Fullerene nanowhiskers (FNWs) are organic semiconductor materials which have a very wide electronics, biomedical, energy and environmental applications in transistors, solar cells, fuel cells, superconductors, cell culture media, catalyst carriers and so forth. It was recently discovered that the electrical resistivity of C60FNWs decreased when they were exposed to the gases with electric dipole moments [1]. This phenomenon is assumed to be caused by the dipole - induced dipole moment interactions between the gas molecules and the  electron systems of C60 molecules. Field-effect transistor (FET) type gas sensors using C60FNWs, silicon substrates and graphite foil electrodes were developed, and their responses for organic gases such as methanol and ethanol were investigated as a function of source-drain and gate bias voltages. Short C60FNWs were packed in a narrow groove between two graphite foil electrodes, and the source-drain current (ISD) was measured through a resistor of 100 M. The ISD increased with the gas exposure time, and linearly varied depending on the gate voltage VG. In addition, flexible FET type gas sensors using C60FNWs and bamboo charcoal cloth were also developed, and their responses for gases such as water and ethanol were investigated as a function of VG and source-drain voltage (VSD). The FNW sensors will be widely applied to environmental, energy and biomedical fields in the future, [1]K. Miyazawa, Y.Tanaka, "All-carbon device application of fullerene nanowhiskers", Meeting abstracts of the Physical Society of Japan, 2025, March, P. 20pJ1-5.

Dr. Kun'ichi Miyazawa is now working with Nano Alloy Technology Inc. (Nagaoka, Japan), and also with Tokyo University of Science as a visiting researcher.　He received Doctor of Engineering degree from The University of Tokyo in 1987. He was a lecturer in the School of Engineering at The University of Tokyo from 1989 to 2002, and moved to National Institute for Materials Science (NIMS) in 2002, where he studied various fullerene nanomaterials including fullerene nanowhiskers as the group leader of Fullerene Engineering Group.　From 2016, he has been mainly engaged in the transmission electron microscopy study of fullerenes, carbon and metal nanomaterials.