US Nuclear Weapons Laboratory Discovers How to Suppress the Casimir Force

[n2doc]

The Casimir effect is a strange and mysterious force that operates on the tiniest scales. It pushes together small metal objects when they are separated by a tiny distance.

That’s a problem because engineers are increasingly interested in building tiny machines with parts that move against each other on precisely the scale. For some years now, they’ve been thwarted by a problem called stiction in which the tiny cogs, gears and other parts in these machines stick together so tightly that the device stops working.

The culprit in these strange stiction events is often the Casimir effect. But since it is poorly understood, physicists and engineers have never known how to prevent it.

That looks set to change thanks to the work of Francesco Intravaia at Los Alamos National Laboratory in New Mexico and a few pals who have discovered a way to reduce this force and showed that it works for the first time.

Los Alamos is best known as a nuclear weapons laboratory but physicists there are also intensely interested in micromachines because they can be used as switches inside weapons that, unlike transistors, cannot be destroyed by intense electromagnetic fields

more

https://medium.com/the-physics-arxiv-blog/8dc2ed4cfd08

[DetlefK]

1. Summed up:

The attractive Casimir-force is messing with their micromachines.

Their solution: The force is weaker if the surface consists of steep hills (200nm high and 200nm wide) instead of a flat surface. They use electron-lithography to achieve that:
Gold-surface.
Cover with a layer of chemical.
Write pattern into that layer by sputtering it with a highly focused electron-beam until they hit gold again. (Editor's note: Takes several hours.)
Then they evaporate gold on their sample, filling the holes and covering everything else. (Editor's note: Including the preparations that takes about half a day.)
Then they wash off the layer of the chemical, also removing the gold on top of the chemical but not the gold inside the depressions.
In the end you get a gold-surface with tiny gold-blocks on it.

Their idea worked.

I doubt, that their method is practical for use in micromachines.
Thin metallic wires are extremely soft. And those nanostructures are even smaller. And gold is especially soft. And their nanostructures aren't crystalline but amorphous gold which yaddayadda missing ES-barrier and temperature yaddayadda might cause nanostructures to become flatter and flatter over time even when the micromachine isn't in use.

[MisterP]

2. "we'll teach YOU to half-exist!"