The Casimir effect in microstructured geometries
Alejandro W. Rodriguez · Federico Capasso · Steven G. Johnson
Summary and citation · read the original at the source
In one page
Alejandro Rodriguez, Federico Capasso and Steven Johnson wrote the invited review that turned the Casimir force from a curiosity into an engineering variable. Hendrik Casimir predicted in 1948 that two metal plates in vacuum would attract, because the quantum fluctuations of the electromagnetic field between them are not the same as the fluctuations outside them. The authors point out that at submicrometre spacings this force is large enough to matter in real micromechanical devices, where it pulls moving parts into contact. Their central argument is that the force is not a fixed law of distance: through its close connection to classical photonics it depends strongly on the shapes and the materials of the objects, and decades of work have gone into finding geometries where it behaves nothing like Casimir’s simple attraction. They survey what that search has produced — predicted repulsion between vacuum-separated metals, stable suspension of one object above another, non-additive and temperature effects, and measured repulsion in fluids and unusual forces over nanotrench surfaces.
Why it matters hereChapter 2 needs the vacuum to be a real medium you can measure, and the Casimir force is where the laboratory touches it; chapter 6 needs that force to be shapeable, because every proposed vacuum energy device — Moddel’s asymmetric resonator, White’s Casimir cell, Chase’s tunnelling diode — depends on breaking the symmetry of the vacuum with geometry and materials. This is the review that maps how far that shaping has already been taken.
What it claims
01In 1948 Hendrik Casimir predicted that a generalized version of van der Waals forces would arise between two metal plates because of quantum fluctuations of the electromagnetic field. The force is a laboratory fact of the electromagnetic vacuum, not a model of it.Abstract, sentence 1; Nature Photonics 5, 211 (2011)
Settled physics02These forces become significant in micromechanical systems at submicrometre scales, for example in the adhesion between movable parts. At device dimensions the vacuum is an engineering load, not a theoretical correction.Abstract, sentence 2
Settled physics03Through its close connection to classical photonics, the Casimir force can depend strongly on the shapes and compositions of the objects involved. That dependence is what has driven a decades-long search for geometries in which the force behaves very differently from the monotonic attraction Casimir first predicted.Abstract, sentence 3
Published and peer-reviewed04Recent theoretical developments reviewed here include predictions of Casimir repulsion between vacuum-separated metals, the stable suspension of objects, and unusual non-additive and temperature effects — that is, configurations where the total force is not the sum of the pairwise attractions and where the sign itself can be designed.Abstract, final sentence, theoretical developments
Published and peer-reviewed05Experimental developments reviewed here include observations of repulsion in fluids, non-additive forces at nanotrench surfaces, and the influence of new material choices. The shaping of the force is measured, not only calculated.Abstract, final sentence, experimental observations
Published and peer-reviewed06What to watch: the review frames geometry and material as the two design variables of the Casimir force, which sets the next measurement for anyone building a vacuum-energy device — a stable, vacuum-separated equilibrium held by shape alone, without an intervening fluid, at a separation and with materials a fabricated device can actually hold.Abstract, read as the review’s programme; Nature Photonics 5, 211 to 221 (2011)
What to watch
The way in
https://doi.org/10.1038/nphoton.2011.39SOURCE NOT REACHED IN FULL. The review is held closed by Nature Photonics; Unpaywall, OpenAlex and Semantic Scholar all report no open version on 2026-09-08, and Steven G. Johnson’s own publication list at the MIT mathematics department carries entry 140 for this paper with a bibliography and DOI link but no author copy of the file. So no text of the review is reproduced here, and the summary and claims are written from the authors’ own abstract as published on that list together with the Crossref record: Nature Photonics, volume 5, pages 211 to 221, March 2011, an invited review. Locators therefore point to the abstract and to the bibliographic record rather than to numbered sections.
How to cite it
Alejandro W. Rodriguez, Federico Capasso, Steven G. Johnson (2011) The Casimir effect in microstructured geometries. doi:10.1038/nphoton.2011.39
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