Heat Transfer Spectroscopy and “Heat Transfer-Distance” Curves

2008 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Sheng Shen ◽  
Gang Chen
Keyword(s):  
Heat Transfer ◽  
Radiative Transfer ◽  
Atomic Force Microscope ◽  
Near Field ◽  
Surface Force ◽  
Casimir Forces ◽  
Distance Curve ◽  
Transfer Distance ◽  
Atomic Force ◽  
Order Of Magnitude

Thermal radiative transfer between objects as well as near-field forces such as van der Waals or Casimir forces have their origins in the fluctuations of the electrodynamic field. Near-field radiative transfer between two objects can be enhanced by a few order of magnitude compared to the far-field radiative transfer that can be described by Planck’s theory of blackbody radiation and Kirchoff’s laws. Despite this common origin, experimental techniques of measuring near-field forces (using the surface force apparatus and the atomic force microscope) are more sophisticated than techniques of measuring near-field radiative transfer. In this work, we present an ultra-sensitive experimental technique of measuring near-field using a bi-material atomic force microscope cantilever as the thermal sensor. Just as measurements of near-field forces results in a “force distance curve”, measurement of near-field radiative transfer results in a “heat transfer-distance” curve. Results from the measurement of near-field radiative transfer will be presented.

Use of the Atomic Force Microscope to Study Mechanical Properties of Lubricant Layers

MRS Bulletin ◽  
1993 ◽  
Vol 18 (5) ◽  
pp. 20-25 ◽  
Author(s):  
Miquel B. Salmeron
Keyword(s):  
Atomic Force Microscope ◽  
Surface Force ◽  
Separation Distance ◽  
Atomic Scale ◽  
Simple Estimate ◽  
Flat Surfaces ◽  
Atomic Force ◽  
Length Increase ◽  
Order Of Magnitude ◽  
Atomically Flat

Advances in our understanding of the phenomena of adhesion, friction, and lubrication are facilitated by the recent development of new tools that allow the study of contacts in close-to-ideal conditions. These new tools are the surface force spparatus (SFA) and the atomic force microscope (AFM). The first was developed by Israelachvili in the 1970s. In this device, contact between two atomically flat surfaces of mica occurs over an area of several micrometers in diameter after the mica sheets, glued onto two perpendicular cylindrical lenses, are compressed. Force, area of contact, and separation distance can be controlled at the atomic scale. The second device, the AFM, was developed by Binnig et al. in 1986. The sharp tip of the AFM is a convenient idealization of a single asperity. In addition, the AFM can be used to image the surface in the weak repulsive or in the attractive modes so that minimum perturbation is introduced by the imaging process itself. These two devices have the necessary sensitivity to allow the application of forces weak enough not to dislodge atoms from their sites during contact. The order of magnitude of the force that can lead to the rupture of chemical bonds is a convenient figure to keep in mind in this context. A simple estimate of this force is obtained by considering a bond-length increase of 1 Å as leading to dissociation. For a bond energy of ≈1 eV, Fb ≈ 1 eV/1 Å ≈ 1 × 10−9 N.

Scanning Near-Field Optical Microscope Study of Ag Nanoprotrusions Fabricated by Nano-oxidation with Atomic Force Microscope

2003 ◽  
Vol 42 (Part 1, No. 12) ◽  
pp. 7635-7639 ◽  
Author(s):  
JunHo Kim ◽  
Jeongyong Kim ◽  
K.-B. Song ◽  
S.-Q. Lee ◽  
E.-K. Kim ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Microscope Study ◽  
Near Field ◽  
Optical Microscope ◽  
Atomic Force

Development of a “Built-in” Scanning Near Field Microscope Head for an Atomic Force Microscope System and Stress Mapping of an Al2O3/ZrO2 Eutectic Composite

2006 ◽  
Vol 13 (4) ◽  
pp. 269-275 ◽  
Author(s):  
Tatsuo Nakagawa ◽  
Satoshi Fukura ◽  
Munenori Nakai ◽  
Kazumasa Sugiyama ◽  
Ryohei Kokawa ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Near Field ◽  
Eutectic Composite ◽  
Atomic Force ◽  
Stress Mapping

Near-Field Radiative Heat Transfer Between Spherical Surfaces

2009 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Sheng Shen ◽  
Gang Chen
Keyword(s):  
Heat Transfer ◽  
Radiative Transfer ◽  
Near Field ◽  
Blackbody Radiation ◽  
Experimental Investigations ◽  
Flat Substrate ◽  
Spherical Surfaces ◽  
Radiation Theory ◽  
Theoretical Predictions ◽  
Afm Cantilever

Nearfield radiative transfer is known to be significantly different from that of far-field radiative transfer based on Plancks theory of blackbody radiation. Theoretical predictions point to a significant enhancement of radiative transfer between closely spaced objects due to the tunneling of surface phonon polaritons. Despite extensive theoretical predictions of enhancement between parallel surfaces, experimental evidence of near-field radiative transfer in excess of Plancks limit has been elusive due to experimental difficulties. In this talk, we will present results of our theoretical and experimental investigations into near-field radiative transfer between spherical surfaces. We have developed a sensitive technique of measuring nearfield radiative transfer between a microsphere and a substrate using a bimaterial atomic force microscope (AFM) cantilever, resulting in heat transfer-distance curves. Measurements of radiative transfer between a sphere and a flat substrate show the presence of strong nearfield effects resulting in enhancement of heat transfer over the predictions of the Planck blackbody radiation theory.

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