Atom balance based on a carbon nanotube resonator
|Yuan-Chih Chang 1, Der-Hsien Lien 1, Shau-Chieh Wang 1, Tung Hsu 2, Chia-Seng Chang 1, Tien-Tzou Tsong 1|
1. Academia Sinica, Taipei, Taiwan
We demonstrate a carbon-nanotube-based resonator with atomic mass resolution. We tailored a multiwalled carbon nanotube (CNT) to possess a resonant frequency over 130 MHz and a Q factor of ~1000. Calculated with the mass of this tube, the mass sensitivity is estimated about 10-22 g. By detecting the resonance frequency shift of this CNT using the STM@TEM system, the mass of a 3 nm Ag particle was estimated to be 0.18x10-18 g, close to the mass of 1000 Ag atoms. Our tailored CNT is thus capable to resolve a single Ag atom and can be named an ‘‘atom-balance’’. It can also be found that the resonance frequency shift due to the Ag particle is sensitive to the Ag particle’s adsorption position on a CNT, as shown in Fig.1. The results are confirmed with the FEM simulation. In addition, when a CNT is driven into resonance under the evaporation of Ag atoms, a gradient distribution of Ag particles along the CNT axis can be assembled (Fig. 2). By combining these techniques, further improvements may conceivably achieve the mass resolution of a light element, which could then enable the elemental or chemical identification.
Presentation: Oral at E-MRS Fall Meeting 2009, Symposium I, by Yuan-Chih Chang
See On-line Journal of E-MRS Fall Meeting 2009
Submitted: 2009-05-11 11:12 Revised: 2009-06-07 00:48