This week, Casimir Inc. emerged from 'stealth mode' to announce it had raised significant funding from venture capitalists willing to roll the dice on free energy. That's right: a startup has gotten serious backing to develop sources of perpetual free energy. The people behind this fantastic new generator also brought us the wildly successful EM-drive - a thruster that could supposedly convert electricity directly into propulsive force. (Its one practical application was in the TV show Salvation, where it was treated with the same detailed attention to physics as Galaxy Quest's Omega-13.) With that track record, who are we to be skeptical?
Casimir Inc. is convinced it can squeeze energy from the vacuum via the Casimir force (hence the subtle name). The Casimir force is real: a vacuum isn't nothing - it's a froth of virtual particles popping into existence, waving, annihilating, and sinking back into the soup. The force emerges when you create an imbalance in the spatial distribution of these particles, causing pressure as the universe tries to equalize. Normally, you could extract a tiny bit of energy from two plates moving together, but you'd lose it all prying them apart again. Casimir Inc. claims a different setup: fixed plates, a row of pillars between them, and a load connected. Details get hazy - or highly obfuscated.
The idea is that electrons will tunnel from plates to pillars but not in reverse. Tunneling is a quantum process where a particle passes through a barrier. Normally, forward and backward tunneling chances are equal, generating no energy. The company's proposed mechanism relies on pillar gaps creating modes like a hydrogen atom's, so electrons go from high-energy to low-energy states. The math looks fine, but the assumption that modes match a hydrogen atom seems shaky. A more plausible route - used in quantum cascade lasers - involves electrons tunneling to a new location, then losing energy via acoustic waves, trapping them. That requires very specific materials and engineering, which probably won't happen here.
Nevertheless, the company claims to have measured a voltage drop between plates and pillars, and that this is predicted in a paper that apparently has no predictions. I'd be shocked if they hadn't measured a potential difference - surfaces are a nightmare. Missing atoms, crystalline boundaries, and impurities from fabrication can generate weird voltages. If they chose the right metal and thin pillars, oxidation on exposure to air could make pillars very different from plates, creating a potential difference independent of any Casimir force.
Even if electron flow occurs, connecting wires introduces potential differences from metal contacts. Charge will accumulate in pillars, reducing the voltage difference and slowing tunneling until the whole pump grinds to a halt. No useful energy will be extracted. But we do value the company's service in burning through a bunch of VC money.