Quantum Mechanical Actuation of Microelectromechanical Systems by the Casimir Force
H. B. Chan · V. A. Aksyuk · R. N. Kleiman · D. J. Bishop · Federico Capasso
Summary and citation · read the original at the source
In one page
The Casimir force is what the vacuum does to two metal surfaces held very close together: shut the longest electromagnetic modes out of the gap and the pressure left outside pushes the surfaces toward each other. Ho Bun Chan, Vladimir Aksyuk, Raymond Kleiman, David Bishop and Federico Capasso, at Bell Laboratories, are the team that made that force do a mechanical job. They built a micromachined torsional device — a doped polysilicon plate hung on two thin rods so that it can tilt — and brought a metallised sphere up to one side of it. The surfaces are uncharged, and the attraction between them still delivers a torque that rotates the plate about its rods. The rotation angle as a function of separation follows the calculated Casimir force. It is the first micromechanical device driven by vacuum fluctuations, and the engineering point lands with it: once parts sit nanometres apart, quantum electrodynamics is part of the mechanical design, not a footnote to it.
Why it matters hereChapter 2 says the vacuum is a real medium that pushes back, and this is the paper where the push became an actuator — a moving part driven by nothing but the field between two uncharged surfaces. Chapter 6 needs exactly that handle: a repeatable, engineered coupling between vacuum fluctuations and mechanical work. Read it beside Fabrizio Pinto’s actuation apparatus at /library/stm-82372e67c9 and Jeremy Munday’s group at /library/stm-b3d5907768, who turn the same force down tenfold or up threefold by shaping the surfaces alone.
What it claims
01The Casimir force is the attraction between uncharged metallic surfaces as a result of quantum mechanical vacuum fluctuations of the electromagnetic field.Abstract, first sentence
Settled physics02The authors demonstrate the Casimir effect in microelectromechanical systems using a micromachined torsional device: attraction between a polysilicon plate and a spherical metallic surface results in a torque that rotates the plate about two thin torsional rods.Abstract, second and third sentences
Settled physics03The dependence of the rotation angle on the separation between the surfaces is in agreement with calculations of the Casimir force.Abstract, fourth sentence
Settled physics04Quantum electrodynamical effects play a significant role in such microelectromechanical systems when the separation between components is in the nanometer range — which makes the vacuum a design parameter for small machines rather than a curiosity.Abstract, final sentence
Settled physics05The device is small and ordinary in its materials: the same authors describe the micromachined oscillator of this device class as a 3.5-micrometre-thick, 500-micrometre-square polysilicon plate metallised on the top with gold, free to rotate about two torsional rods on opposite edges, with a gold-metallised polystyrene sphere 200 micrometres in diameter brought up to one side.Companion paper, Chan et al., Nonlinear micromechanical Casimir oscillator, arXiv quant-ph/0109046, paragraph beginning ’We realize such an oscillator’, which cites this paper as its reference 5
Published and peer-reviewed06When the sphere was moved closer to the plate in a vacuum at a pressure below one millitorr, the Casimir force acting on the plate tilted it about its central axis toward the sphere — vacuum oscillations of the electromagnetic field producing mechanical motion, in the first micromechanical device driven by the Casimir force — and comparing the measured force with the ideal-metal Casimir result showed the influence of skin depth and surface roughness on the force between real materials.As summarised in Klimchitskaya, Mohideen and Mostepanenko, The Casimir force between real materials, section IV.C.2, on this site at /library/stm-7e33aa610f
Settled physics
The way in
https://doi.org/10.1126/science.1057984Science 291, issue 5510, pages 1941-1944, published 9 March 2001; the work was done at Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey. RIGHTS AND TEXT. The Crossref record carries no licence statement, Unpaywall and OpenAlex record no open version, and the publisher’s pages decline automated retrieval, so the article was not read for this page. The authors’ own abstract, as indexed for this DOI by Crossref and OpenAlex from the publisher’s record, was read on 2026-09-08 and is the source of the claims located to ’Abstract’. Two claims about the apparatus are located outside the abstract and say so: one to the same authors’ companion paper of the same year, ’Nonlinear micromechanical Casimir oscillator’, Physical Review Letters 87, 211801, read in full from the author version at arXiv quant-ph/0109046, which describes the same class of device and cites this paper as its static-measurement predecessor; and one to the account of this experiment in the Klimchitskaya, Mohideen and Mostepanenko review, section IV.C.2, which is carried on this site at /library/stm-7e33aa610f. No reproduced text appears on this page.
How to cite it
H. B. Chan, V. A. Aksyuk, R. N. Kleiman, D. J. Bishop, Federico Capasso (2001) Quantum Mechanical Actuation of Microelectromechanical Systems by the Casimir Force. doi:10.1126/science.1057984
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