Torsional Resonators Based on Inorganic Nanotubes

The use of various nanostructures such as nanotubes and 2D sheets in electrical and electromechanical devices is the subject of intensive research in recent years. In particular, the electronic properties of inorganic compounds such as the dichlcogenides sparked the research of their incorporation into nano-electro-mechanical systems (NEMS). WS₂ nanotubes (INT-WS₂) exhibit superior mechanical properties, interesting stick-slip mechanical phenomena¹, significant field-effect mobility, high current carrying capacity² and thus are a natural candidate for electro-mechanical devices. The torsional behavior of nanotubes is highly affected by factors like chemical composition and structure and exploring nanotubes of different materials could expand the arsenal of building blocks for future NEMS designers.

We show here for the first time³ the resonant torsional behaviors of inorganic nanotubes, specifically tungsten disulfide (WS₂) and boron nitride (BN) nanotubes, and compare them to that of carbon nanotubes. We have found WS₂ nanotubes to have the highest quality factor (Q) and torsional resonance frequency, followed by BN nanotubes and carbon nanotubes. Dynamic and static torsional spring constants of the various nanotubes were found to be different, especially in the case of WS₂, possibly due to a velocity dependent intershell friction. These results indicate that inorganic nanotubes are promising building blocks for high-Q nanoelectromechanical systems (NEMS).

References

1. Nagapriya, K. S.; Goldbart, O.; Kaplan-Ashiri, I.; Seifert, G.; Tenne, R.; Joselevich, E. Physical Review Letters 2008, 101, (19), 195501.
2. Levi, R.; Bitton, O.; Leitus, G.; Tenne, R.; Joselevich, E. Nano Letters 2013, 13, (8), 3736-3741.
3. Divon, Y.; Levi, R.; Garel, J.; Golberg, D.; Tenne, R.; Ya’akobovitz, A.; Joselevich, E. Nano Letters 2017, 17, (1), 28-35.