Historical research guide · 0714 · 2008
Membrane actuation by Casimir force manipulation
Fabrizio Pinto
In one minute
The Casimir force is the vacuum pressing two close-set surfaces together, and below a micrometre it is the strongest thing acting on a small machined part — which is why it is usually written about as a nuisance that makes tiny mechanisms stick. Fabrizio Pinto’s question is what happens when you stop treating it that way and start using it as a motor. Here he reports on a laboratory apparatus built to demonstrate actuation by the Casimir force, taking as its starting point the capacitive detection scheme Arnold, Hunklinger and Dransfeld published in 1972 and rebuilding it around modern nanopositioner technology. Most of the work is in the two things such a device needs before it can claim a force at all: an electrostatic calibration accurate enough to subtract, which sent Pinto back to the classical problem of the field between two circular plates, and a computation of the Casimir force itself in an axial geometry. The measurement he reports is of a vibrating membrane with a central disc.
Connection
Chapter 2 says the vacuum is a real medium you can measure pushing back, and chapter 6 asks for a handle an engineer can turn. This paper is the engineering end of that: not a demonstration that the Casimir force exists, but an apparatus, a calibration procedure and a resonance measurement aimed squarely at products. Pinto’s closing argument — that dispersion forces may support a new and rapidly expanding industry — is the same bet the modern geometry work makes from the other side, and the companion sheet is Munday’s group at /library/stm-b3d5907768, who show the same force turned down tenfold or up threefold by shape alone, in the same two chapters.
From the source
Pinto’s laboratory has been developing a practical demonstration of actuation by means of the Casimir force, taking as its starting point the capacitive detection approach originally described by Arnold, Hunklinger and Dransfeld in 1972.Abstract, first sentence
The electrostatic calibration of the measuring device set mathematical challenges of its own, which the author addresses with recently published results on the computation of electrostatic fields in axial systems, including the long-standing classical circular capacitor problem.Abstract, second sentence
The Casimir force in the apparatus is computed by adopting analytical descriptions of the dielectric functions of semiconductors, extended to the case of axial geometries.Abstract, third sentence
The original 1972 apparatus has been drastically improved upon, for instance by means of modern nanopositioner technology, and the author’s published experimental results on the dynamics of a vibrating membrane with a central disc provided the first direct verification of the mechanical resonances of such a system.Abstract, fourth sentence
The stated emphasis of the effort is not exclusively fundamental physics research but the identification of viable industrial applications leading to commercially marketable products based on Casimir force actuation, and Pinto closes by arguing that dispersion forces may enable a new and rapidly expanding industry to develop in the near future, in nanotechnology among other fields.Abstract, closing sentences
The way in
https://doi.org/10.1088/1751-8113/41/16/164033How to cite it
Fabrizio Pinto (2008) Membrane actuation by Casimir force manipulation doi:10.1088/1751-8113/41/16/164033