Torsional Resonators Based on Inorganic Nanotubes

The use of various inorganic nanostructures such as nanotubes (INT) and 2D sheets in nano-electro-mechanical systems (NEMS) is the subject of intensive research in recent years. WS₂ nanotubes 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.
We show here for the first time³ the resonant torsional behaviors of INT, specifically WS₂NT and BNNT, and compare them to that of carbon NT (CNT). We have found WS₂NT to have the highest quality factor (Q) and torsional resonance frequency, followed by BNNT and CNT. The dynamic and static torsional spring constants of the NT were found to be different, especially in the case of WS₂, likely due to a velocity dependent intershell friction. These results indicate that INT are promising building blocks for high-Q NEMS.
References
1. Nagapriya, K. S.; Goldbart, O.; Kaplan-Ashiri, I.; Seifert, G.; Tenne, R.; Joselevich, E. Physical Review Letters 2008, 101, 195501.
2. Levi, R.; Bitton, O.; Leitus, G.; Tenne, R.; Joselevich, E. Nano Letters 2013, 13, 3736-3741.
3. Divon, Y.; Levi, R.; Garel, J.; Golberg, D.; Tenne, R.; Ya’akobovitz, A.; Joselevich, E. Nano Letters 2017, 17, 28-35.