Lab talk
Feb 3, 2012
Electrically driven gallium movement in carbon nanotubes
Carbon nanotubes (CNTs) filled with metals have been shown to behave as small mass conveyers, a property that could be exploited in various applications.
In a recent study, scientists have investigated electrical driven mass delivery at a higher current (~15 mA) and resistance changes at a lower current (~2 mA) in two different Ga-filled CNTs. Gallium is a good electrical and thermal conductor, and has the highest liquid range (29.78–2403 °C) among all metals.
Nanoswitches and delivery systems
A higher current (~15 mA) makes the gallium migrate sharply towards the anode, which increases its mass transport speed with time, in the range of 0 to more than 10.345 fg s–1. In contrast, a lower current (~2 mA) only drives gallium to contact the anode, which decreases the resistance of the nanocomposite sharply, from 2.564 kΩ to 0.4 Ω. These results are valuable for the design of electrically driven nanomass delivery systems and nanoswitches.
More details can be found in the journal Nanotechnology.
About the author
Yihua Gao received his PhD in 1998. He studied at the Institute of Physics, Chinese Academy of Sciences and then became a special researcher at the National Institute for Materials Science (NIMS) in Japan. His research interests include semiconductor films, microstructures, nanomaterials and nanodevices. On 7 February 2002, Dr Gao and Prof. Yoshio Bando reported the world's smallest thermometer – a carbon nanothermometer – in Nature 415 599. On 30 Sept 2005, Dr Gao received the 16th Tsukuba Prize together with Prof. Y Bando and Prof. D Golberg. In March 2006, Dr Gao accepted a professorship at Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology (HUST, Wuhan). Now, Prof. Gao is continuing his research in the field of 1D nanoscience and nanotechnology. Projects include (1) Dynamic-thermal-electric effects in Ga-In filling nanotubes; (2) Light emission in GaN/ZnO nano arrays; (3) Nanomaterials for enhancing harvesting efficiency in flexiblesolar cells. Dr Min Sun is a former student of Prof. Gao.
