Based on surface tension has been devised. Physicists at the University of California, Berkeley put two molten metal droplets—one of 30- and one of 90-nm radius—on the spine of a carbon nanotube. With a small DC voltage applied, atoms diffused along the CNT from the large drop to the small one, whose radius grew much faster than the large one’s shrank. In effect, potential energy was stored as surface tension in the smaller droplet. Eventually, the drops touched, and the higher internal pressure of the smaller one very rapidly drove the fluid back into the bigger one through the newly opened hydrodynamic channel. The cycle (shown in the photos) then repeated. The device is a “relaxation oscillator,” with a slow buildup and a rapid release of energy. Varying the voltage easily changes the operating frequency—a complete cycle took about 30 s at 1.3 V, about 6 s at 1.4...
Skip Nav Destination
Article navigation
1 June 2005
June 01 2005
Citation
Phillip F. Schewe; A nanoscale electric motor. Physics Today 1 June 2005; 58 (6): 9. https://doi.org/10.1063/1.4797079
Download citation file:
PERSONAL SUBSCRIPTION
Purchase an annual subscription for $25. A subscription grants you access to all of Physics Today's current and backfile content.
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
25
Views
Citing articles via
The lessons learned from ephemeral nuclei
Witold Nazarewicz; Lee G. Sobotka
FYI science policy briefs
Lindsay McKenzie; Jacob Taylor