When two objects are placed extremely close together, they will be attracted to each other by this only recently proven to exist quantum force. Instead of the objects' masses pulling them together, Casimir force works as an external force, almost like hydrodynamic pressure.

In this case, the empty space between the two objects isn't actually empty. All space is filled with electromagnetic fields and the virtual particles associated with them. These particles, in quantum physics, also exist as waves, and here's where things start to make sense. Around the objects, these particle/waves can be of any varying wavelength, but only a smaller number of shorter wavelength particles can fit between them. This creates a sort of low versus high pressure system where the force of the “heavier” longer wavelength particles acts to push the masses together.

UF's research into this interesting force may, in the future, help the ever growing miniaturization of electronic components. As MEMS (microelectricalmechanical) devices get smaller and stacked closer together, the likelihood of the Casimir force becoming a problem gets larger. “Stiction” is already a problem in super-fine structure assembly, and though it can be caused by a number of variables, the Casimir force can easily contribute to it.

In a paper published in Physical Review Letters, lead-author Ho Bun Chan explains, “We are not talking about an immediate application, we are talking about, if the devices continue to be smaller and smaller, as the trend of miniaturization occurs, then the quantum effects could come into play.”

With integrated circuits and other electronic parts rapidly losing size but gaining parts and complexity, these effects could easily occur in the next decade.

To study how Casimir force can be affected by structure, the UF team created a metal panel resembling a fin radiator, with fin structures of approximately 200nm separated by the same distance. This effectively cut the gapped surface area in half compared to two flat plates that were used as a control. They found that, though having more area between the plates for longer wavelength particles to occupy and half the accessible surface area, the comb-like structure only reduced Casimir force by 30 to 40 percent.

While the experiment didn't show the expected 50 percent reduction, it helped prove that, instead, the strength of the Casimir force depends on the geometry of the objects in question. This may be useful in the future for MEMS and other nanomachinery engineers as they need to design nanoscopic parts that would not work well if they were heavily affected by the mysterious quantum particles.