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Ultrafast nano-oscillators based on interlayer-bridged carbon nanoscrolls.

Zhang Z, Li T - Nanoscale Res Lett (2011)

Bottom Line: We demonstrate an effective strategy to reduce the dissipation of the CNS-based nano-oscillator by covalently bridging the carbon layers in the CNS.We further demonstrate that such a CNS-based nano-oscillator can be excited and driven by an external AC electric field, and oscillate at more than 100 GHz.The CNS-based nano-oscillators not only offer a feasible pathway toward ultrafast nano-devices but also hold promise to enable nanoscale energy transduction, harnessing, and storage (e.g., from electric to mechanical).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA. LiT@umd.edu.

ABSTRACT
We demonstrate a viable approach to fabricating ultrafast axial nano-oscillators based on carbon nanoscrolls (CNSs) using molecular dynamics simulations. Initiated by a single-walled carbon nanotube (CNT), a monolayer graphene can continuously scroll into a CNS with the CNT housed inside. The CNT inside the CNS can oscillate along axial direction at a natural frequency of tens of gigahertz. We demonstrate an effective strategy to reduce the dissipation of the CNS-based nano-oscillator by covalently bridging the carbon layers in the CNS. We further demonstrate that such a CNS-based nano-oscillator can be excited and driven by an external AC electric field, and oscillate at more than 100 GHz. The CNS-based nano-oscillators not only offer a feasible pathway toward ultrafast nano-devices but also hold promise to enable nanoscale energy transduction, harnessing, and storage (e.g., from electric to mechanical).

No MeSH data available.


Related in: MedlinePlus

Oscillation of a CNT housed inside a naturally formed CNS. (a) Snapshots of the axial oscillation of the CNS-based nano-oscillator at 5, 15, 20, 30, 40, and 50 ps, respectively. Note the coupled axial oscillations of the CNT and the CNS itself. The evolution of (b) the absolute amplitude and (d) the relative amplitude of the CNT oscillation inside the CNS, as a function of simulation time, respectively. The FFT analysis of the absolute amplitude (c) and the relative amplitude (e) for the first 500 ps reveals a frequency of the oscillation of the CNT inside the CNS (29.4 GHz) and that of the oscillation of the CNS itself (50.9 GHz), respectively. The simulations are carried out at 100 K.
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Figure 3: Oscillation of a CNT housed inside a naturally formed CNS. (a) Snapshots of the axial oscillation of the CNS-based nano-oscillator at 5, 15, 20, 30, 40, and 50 ps, respectively. Note the coupled axial oscillations of the CNT and the CNS itself. The evolution of (b) the absolute amplitude and (d) the relative amplitude of the CNT oscillation inside the CNS, as a function of simulation time, respectively. The FFT analysis of the absolute amplitude (c) and the relative amplitude (e) for the first 500 ps reveals a frequency of the oscillation of the CNT inside the CNS (29.4 GHz) and that of the oscillation of the CNS itself (50.9 GHz), respectively. The simulations are carried out at 100 K.

Mentions: The CNS-based nano-oscillator formed by scrolling up a pristine graphene is first equilibrated for 50 ps at 100 K, and then, the CNT housed inside is assigned a velocity 2.5 Å/ps along its axial direction to initiate the oscillation. In order to constrain the rigid body motion of the nano-oscillator, two rows of carbon atoms along the axial direction on the outermost shell of the CNS are fixed. Figure 3a shows the snapshots of the axial oscillation of the CNS/CNT nanostructure at 5, 15, 20, 30, 40, and 50 ps, respectively (see Additional file 2 for a video of the oscillation). The simulations are carried out at 100 K. The axial motion of the CNT is excluded in the calculation of temperature. Besides the oscillation of the CNT inside the CNS, the CNS itself also oscillates through interlayer relative sliding in axial direction, initiated by the reaction force from the CNT (i.e., opposite to the restoring force applied on the CNT). The reaction force pulls the inner shells of the CNS to slide outward during the CNT oscillation; thus, the CNS itself starts to oscillate accompanying the CNT motion. As a result, the oscillation of the CNS/CNT nanostructure is indeed the coupled CNT oscillation and that of the CNS itself. It needs to be pointed out that the CNS self-oscillation is not only driven by the van der Waals-type reaction force between the CNS and the CNT but also affected by the in-plane shear rigidity of the basal graphene. The different energetic interplays for the CNT oscillation and the CNS self-oscillation lead to a rather irregular coupled oscillation, similar to the axial oscillation observed in a MWCNT [26].


Ultrafast nano-oscillators based on interlayer-bridged carbon nanoscrolls.

Zhang Z, Li T - Nanoscale Res Lett (2011)

Oscillation of a CNT housed inside a naturally formed CNS. (a) Snapshots of the axial oscillation of the CNS-based nano-oscillator at 5, 15, 20, 30, 40, and 50 ps, respectively. Note the coupled axial oscillations of the CNT and the CNS itself. The evolution of (b) the absolute amplitude and (d) the relative amplitude of the CNT oscillation inside the CNS, as a function of simulation time, respectively. The FFT analysis of the absolute amplitude (c) and the relative amplitude (e) for the first 500 ps reveals a frequency of the oscillation of the CNT inside the CNS (29.4 GHz) and that of the oscillation of the CNS itself (50.9 GHz), respectively. The simulations are carried out at 100 K.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211983&req=5

Figure 3: Oscillation of a CNT housed inside a naturally formed CNS. (a) Snapshots of the axial oscillation of the CNS-based nano-oscillator at 5, 15, 20, 30, 40, and 50 ps, respectively. Note the coupled axial oscillations of the CNT and the CNS itself. The evolution of (b) the absolute amplitude and (d) the relative amplitude of the CNT oscillation inside the CNS, as a function of simulation time, respectively. The FFT analysis of the absolute amplitude (c) and the relative amplitude (e) for the first 500 ps reveals a frequency of the oscillation of the CNT inside the CNS (29.4 GHz) and that of the oscillation of the CNS itself (50.9 GHz), respectively. The simulations are carried out at 100 K.
Mentions: The CNS-based nano-oscillator formed by scrolling up a pristine graphene is first equilibrated for 50 ps at 100 K, and then, the CNT housed inside is assigned a velocity 2.5 Å/ps along its axial direction to initiate the oscillation. In order to constrain the rigid body motion of the nano-oscillator, two rows of carbon atoms along the axial direction on the outermost shell of the CNS are fixed. Figure 3a shows the snapshots of the axial oscillation of the CNS/CNT nanostructure at 5, 15, 20, 30, 40, and 50 ps, respectively (see Additional file 2 for a video of the oscillation). The simulations are carried out at 100 K. The axial motion of the CNT is excluded in the calculation of temperature. Besides the oscillation of the CNT inside the CNS, the CNS itself also oscillates through interlayer relative sliding in axial direction, initiated by the reaction force from the CNT (i.e., opposite to the restoring force applied on the CNT). The reaction force pulls the inner shells of the CNS to slide outward during the CNT oscillation; thus, the CNS itself starts to oscillate accompanying the CNT motion. As a result, the oscillation of the CNS/CNT nanostructure is indeed the coupled CNT oscillation and that of the CNS itself. It needs to be pointed out that the CNS self-oscillation is not only driven by the van der Waals-type reaction force between the CNS and the CNT but also affected by the in-plane shear rigidity of the basal graphene. The different energetic interplays for the CNT oscillation and the CNS self-oscillation lead to a rather irregular coupled oscillation, similar to the axial oscillation observed in a MWCNT [26].

Bottom Line: We demonstrate an effective strategy to reduce the dissipation of the CNS-based nano-oscillator by covalently bridging the carbon layers in the CNS.We further demonstrate that such a CNS-based nano-oscillator can be excited and driven by an external AC electric field, and oscillate at more than 100 GHz.The CNS-based nano-oscillators not only offer a feasible pathway toward ultrafast nano-devices but also hold promise to enable nanoscale energy transduction, harnessing, and storage (e.g., from electric to mechanical).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA. LiT@umd.edu.

ABSTRACT
We demonstrate a viable approach to fabricating ultrafast axial nano-oscillators based on carbon nanoscrolls (CNSs) using molecular dynamics simulations. Initiated by a single-walled carbon nanotube (CNT), a monolayer graphene can continuously scroll into a CNS with the CNT housed inside. The CNT inside the CNS can oscillate along axial direction at a natural frequency of tens of gigahertz. We demonstrate an effective strategy to reduce the dissipation of the CNS-based nano-oscillator by covalently bridging the carbon layers in the CNS. We further demonstrate that such a CNS-based nano-oscillator can be excited and driven by an external AC electric field, and oscillate at more than 100 GHz. The CNS-based nano-oscillators not only offer a feasible pathway toward ultrafast nano-devices but also hold promise to enable nanoscale energy transduction, harnessing, and storage (e.g., from electric to mechanical).

No MeSH data available.


Related in: MedlinePlus