Subnanometer Motion of Cargoes Driven by Thermal Gradients Along Carbon Nanotubes

Barreiro, Amelia; Rurali, Riccardo; Hernández, Eduardo; Moser, J.; Pichler, Thomas; Forró, Lászlø; Bachtold, Adrian

doi:10.1126/science.1155559

Cited by 356 publications

(422 citation statements)

References 25 publications

Supporting

Mentioning

394

Contrasting

Unclassified

Order By: Relevance

“…contains information about the protocol and the coupling mechanism between the colloidal particle and the thermal environment. We find excellent agreement between equation (2) (solid line) and our data when the fitting parameter E is adjusted to E = 0.95 k 8 Tcs.…”

supporting

confidence: 63%

Realization of a micrometre-sized stochastic heat engine

2011

View full text Add to dashboard Cite

The conversion of energy into mechanical work is essential for almost any industrial process. The original description of classical heat engines by Sadi Carnot in 1824 has largely shaped our understanding of work and heat exchange during macroscopic thermodynamic processes 1 . Equipped with our present-day ability to design and control mechanical devices at micro-and nanometre length scales, we are now in a position to explore the limitations of classical thermodynamics, arising on scales for which thermal fluctuations are important 2-5 . Here we demonstrate the experimental realization of a microscopic heat engine, comprising a single colloidal particle subject to a time-dependent optical laser trap. The work associated with the system is a fluctuating quantity, and depends strongly on the cycle duration time, τ, which in turn determines the efficiency of our heat engine. Our experiments offer a rare insight into the conversion of thermal to mechanical energy on a microscopic level, and pave the way for the design of future micromechanical machines.Macroscopic heat engines operating periodically between two heat baths are described well by the laws of thermodynamics, owing to the large number of internal degrees of freedom, which render fluctuations negligible. In contrast, fluctuations become visible when the typical energy scales of engines are reduced by more than twenty orders of magnitude, down to values around k B T . This regime can be achieved when the typical system dimensions are scaled down from metres to micrometres 2 . Such conditions are typically met for biomolecules 6,7 and other microelectromechanical systems (MEMS; refs 8-10) that can perform translational or rotational motion as a result of chemical reactions and electrical fields. Also, several types of Brownian motor have been discussed that are able to extract useful work by rectification of thermal noise [11][12][13] . Despite its conceptual simplicity, no attempt has been made to realize a microscopic heat engine that extracts energy by cyclically working between two heat baths in a regime where fluctuations dominate.Here we present an experimental realization of a Stirling engine, where a single Brownian particle is subjected to a time-dependent optical trap and periodically coupled to different heat baths 14 . The particle and the trapping potential replace the working gas and the piston of its macroscopic counterpart. As for conventional heat engines where the periodic coupling of the working gas to a cold and a hot heat bath changes volume and pressure inside a piston, the fluctuations of a colloidal particle subjected to an external optical potential vary on changing the temperature of the solvent.As a Brownian particle we used a single melamine bead of diameter 2.94 μm suspended in water and confined in a vitreous sample cell 4 μm in height. Using a highly focused infrared laser beam we exerted a parabolic trapping potential U (R,k) = (1/2)k(t )R 2 on the particle, where R is its radial distance from the trapping centre and k(t ), ...

show abstract

supporting

confidence: 63%

Realization of a micrometre-sized stochastic heat engine

2011

View full text Add to dashboard Cite

show abstract

“…The capsule travels back and forth between both ends of the host carbon nanotube along the axial direction. Barreiro et al have designed an artificial nanofabricated motor in which one short carbon nanotube travels relative to another coaxial carbon nanotube [7]. This motion is actuated by a thermal gradient as high as 1 K nm −1 applied to the ends of the coaxial carbon nanotubes.…”

Section: Introductionmentioning

confidence: 99%

“…The two-dimensional structure of graphene suggests the possibility of motion with just two degrees of freedom. The free energy surface for a particle moving above a graphene sheet explains different motion-related phenomena at nanoscale as well as the various directed motions on the carbon nanotube-based motors [6,7].…”

Section: Introductionmentioning

confidence: 99%

Directed motion ofC60on a graphene sheet subjected to a temperature gradient

2011

View full text Add to dashboard Cite

Nonequilibrium molecular dynamics simulations is used to study the motion of a C60 molecule on a graphene sheet subjected to a temperature gradient. The C60 molecule is actuated and moves along the system while it just randomly dances along the perpendicular direction. Increasing the temperature gradient increases the directed velocity of C60. It is found that the free energy decreases as the C60 molecule moves toward the cold end. The driving mechanism based on the temperature gradient suggests the construction of nanoscale graphene-based motors.

show abstract

“…These processes involve relative sliding of the layers, which exhibits a corrugated energy landscape even in atomically flat systems, such as graphite and hexagonal boron nitride (h-BN). This corrugation arises from the non-uniform charge density distribution around the atomic positions within each layer [7][8][9]. It is well accepted that the most important factors that govern corrugation in such system are electrostatic and dispersion interactions.…”

mentioning

confidence: 99%

Stacking and Registry Effects in Layered Materials: The Case of Hexagonal Boron Nitride

et al. 2010

View full text Add to dashboard Cite

The interlayer sliding energy landscape of hexagonal boron nitride (h-BN) is investigated via a van der Waals corrected density functional theory approach. It is found that the main role of the van der Waals forces is to "anchor" the layers at a fixed distance, whereas the electrostatic forces dictate the optimal stacking mode and the interlayer sliding energy. A nearly free-sliding path is identified, along which bandgap modulations of ∼ 0.6 eV are obtained. We propose a simple geometrical model that quantifies the registry matching between the layers and captures the essence of the corrugated h-BN interlayer energy landscape. The simplicity of this phenomenological model opens the way to the modeling of complex layered structures, such as carbon and boron nitride nanotubes.The interlayer potential landscape in layered materials is essential for understanding their mechanical and electromechanical behavior. For example, nanoelectromechanical systems (NEMS) based on low dimensional structures of such materials often rely on mechanical deformations such as twisting [1][2][3] and bending [4][5][6]. These processes involve relative sliding of the layers, which exhibits a corrugated energy landscape even in atomically flat systems, such as graphite and hexagonal boron nitride (h-BN). This corrugation arises from the non-uniform charge density distribution around the atomic positions within each layer [7][8][9]. It is well accepted that the most important factors that govern corrugation in such system are electrostatic and dispersion interactions. However, a clear picture of how the complex interplay between these factors determines the corrugated energy landscape and its manifestation in unique material properties has not emerged yet.Previous efforts towards the understanding of these phenomena have utilized density functional theory (DFT) with (semi-)local approximations [9][10][11][12]. However, these methods do not provide an appropriate description of dispersive interactions. Several approaches within DFT have been developed to overcome this problem, demonstrating successful treatment of dispersion effects in graphite [13][14][15] and h-BN [13,14,16]. However, to the best of our knowledge, such studies have not addressed the question of corrugation.In this letter, we present a theoretical study of the intricate interplay between dispersion and electrostatic interactions in layered materials. As an illustrative example we choose the case of h-BN, where both types of interactions are expected to have a considerable influence on the landscape of the interlayer potential. Using a first-principles van der Waals (vdW) corrected DFT approach, we show that dispersion interactions play the role of fixing the interlayer distance, while the electrostatic forces determine the optimal stacking mode and the interlayer sliding corrugation. In addition, we predict the existence of a nearly free-sliding path along which considerable bandgap modulations are obtained. Finally, we propose a simple geometrical model that quantifies ...

show abstract

Subnanometer Motion of Cargoes Driven by Thermal Gradients Along Carbon Nanotubes

Cited by 356 publications

References 25 publications

Realization of a micrometre-sized stochastic heat engine

Realization of a micrometre-sized stochastic heat engine

Directed motion ofC60on a graphene sheet subjected to a temperature gradient

Stacking and Registry Effects in Layered Materials: The Case of Hexagonal Boron Nitride

Contact Info

Product

Resources

About