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Journal ArticleDOI

Atomic force microscope

03 Mar 1986-Physical Review Letters (American Physical Society)-Vol. 56, Iss: 9, pp 930-933
TL;DR: The atomic force microscope as mentioned in this paper is a combination of the principles of the scanning tunneling microscope and the stylus profilometer, which was proposed as a method to measure forces as small as 10-18 N. As one application for this concept, they introduce a new type of microscope capable of investigating surfaces of insulators on an atomic scale.
Abstract: The scanning tunneling microscope is proposed as a method to measure forces as small as 10-18 N. As one application for this concept, we introduce a new type of microscope capable of investigating surfaces of insulators on an atomic scale. The atomic force microscope is a combination of the principles of the scanning tunneling microscope and the stylus profilometer. It incorporates a probe that does not damage the surface. Our preliminary results in air demonstrate a lateral resolution of 30 A and a vertical resolution less than 1 A.
Citations
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Journal ArticleDOI
TL;DR: In this article, the authors describe a simple, nondestructive procedure for measuring the force constant, resonant frequency, and quality factor of an AFM cantilever spring and the effective radius of curvature of an AU tip.
Abstract: Images and force measurements taken by an atomic‐force microscope (AFM) depend greatly on the properties of the spring and tip used to probe the sample’s surface. In this article, we describe a simple, nondestructive procedure for measuring the force constant, resonant frequency, and quality factor of an AFM cantilever spring and the effective radius of curvature of an AFM tip. Our procedure uses the AFM itself and does not require additional equipment.

3,975 citations

Journal ArticleDOI
TL;DR: The atomic force microscope (AFM) is not only used to image the topography of solid surfaces at high resolution but also to measure force-versus-distance curves as discussed by the authors, which provide valuable information on local material properties such as elasticity, hardness, Hamaker constant, adhesion and surface charge densities.

3,281 citations

Journal ArticleDOI
16 May 1997-Science
TL;DR: Single-molecule atomic force microscopy was used to investigate the mechanical properties of titin, the giant sarcomeric protein of striated muscle, and refolding of immunoglobulin domains was observed.
Abstract: Single-molecule atomic force microscopy (AFM) was used to investigate the mechanical properties of titin, the giant sarcomeric protein of striated muscle. Individual titin molecules were repeatedly stretched, and the applied force was recorded as a function of the elongation. At large extensions, the restoring force exhibited a sawtoothlike pattern, with a periodicity that varied between 25 and 28 nanometers. Measurements of recombinant titin immunoglobulin segments of two different lengths exhibited the same pattern and allowed attribution of the discontinuities to the unfolding of individual immunoglobulin domains. The forces required to unfold individual domains ranged from 150 to 300 piconewtons and depended on the pulling speed. Upon relaxation, refolding of immunoglobulin domains was observed.

2,959 citations

Journal ArticleDOI
TL;DR: A review of the literature on thermal transport in nanoscale devices can be found in this article, where the authors highlight the recent developments in experiment, theory and computation that have occurred in the past ten years and summarizes the present status of the field.
Abstract: Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid–solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime—experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management of optoelectronic devices have stimulated extensive studies of semiconductor superlattices; agreement between experiment and theory is generally poor. Advances in measurement methods, e.g., the 3ω method, time-domain thermoreflectance, sources of coherent phonons, microfabricated test structures, and the scanning thermal microscope, are enabling new capabilities for nanoscale thermal metrology.

2,933 citations

Journal ArticleDOI
06 Aug 1998-Nature
TL;DR: The design and observation of two-dimensional crystalline forms of DNA that self-assemble from synthetic DNA double-crossover molecules that create specific periodic patterns on the nanometre scale are reported.
Abstract: Molecular self-assembly presents a `bottom-up' approach to the fabrication of objects specified with nanometre precision. DNA molecular structures and intermolecular interactions are particularly amenable to the design and synthesis of complex molecular objects. We report the design and observation of two-dimensional crystalline forms of DNA that self-assemble from synthetic DNA double-crossover molecules. Intermolecular interactions between the structural units are programmed by the design of `sticky ends' that associate according to Watson-Crick complementarity, enabling us to create specific periodic patterns on the nanometre scale. The patterned crystals have been visualized by atomic force microscopy.

2,713 citations

References
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Journal ArticleDOI
TL;DR: In this paper several useful methods and instruments—total integrated scattering, stylus profilometer, optical heterodyne profilometers, variable angle scatterometer, and electron mirror interference microscope—are presented.
Abstract: The surface roughness of low-scatter mirrors and roughness standards can be measured in various ways: mechanically, optically, and electronoptically. In this paper several useful methods and instruments—total integrated scattering, stylus profilometer, optical heterodyne profilometer, variable angle scatterometer, and electron mirror interference microscope—are presented. Qualitative surface roughness assessment is provided by Nomarski microscopy and transmission electron microscopy of surface replicas. Samples were prepared at Balzers, and their surface roughness was measured at several laboratories using the methods given above. The results of these measurements are compared, and reasons for the differences are discussed.

117 citations

Journal ArticleDOI
01 Dec 1982-Wear
TL;DR: In this article, a computer-based system for transforming the surface topography of a specimen into an intensity image is presented together with a method of three-dimensional stylus profilometry.

72 citations

Journal ArticleDOI
TL;DR: In this paper, a device permitting simultaneous x-ray and optical interferometry over traverses in excess of 20 μm is reported, and results obtained to date suggest that such devices will permit measurements of certain crystal lattice spacings with accuracies better than one part per million.
Abstract: A device permitting simultaneous x‐ray and optical interferometry over traverses in excess of 20 μm is reported. Results obtained to date suggest that such devices will permit measurements of certain crystal‐lattice spacings with accuracies better than one part per million.

48 citations

Journal ArticleDOI
01 Dec 1982-Wear
TL;DR: In this article, the effects of experimental technique on the assessment of engineering surfaces by stylus profilometry are considered, and it is shown that some of the variation in surface statistics obtained is a result of tracking inaccuracy, filtering of data by the choice of skid or datum, surface damage caused by the stylus and skid, and substantial errors caused by particles attaching themselves to the surface under assessment.

18 citations