According to various sources, the Casimir effect could theoretically be used to stabilize a two-way wormhole because it "simulates" the negative energy exotic matter that would normally be required. For this to work, would you literally sandwich a wormhole between two plates? I've heard that it might actually involve positioning charged metal balls in the mouths, but the linked article was behind a paywall.
[Physics] How would the Casimir effect stabilize wormholes
casimir-effectexotic-matterwormholes
Best Answer
The Casimir effect is of interest because it is one of the earliest effect that was discovered to violate most energy conditions without any restrictions - it produces negative energies in a static manner. As such, it violates the Null Energy Condition, the Averaged Null Energy Condition and is not constrained all that much by the Quantum Inequalities.
While that is all very good, it also has quite a few drawbacks. The Casimir effect is very small, it requires very close proximity of two conductors, real conductors are not perfect conductors which makes it even less pronounced in real applications, and of course, the most important part, there are two giants sources of energy right next to it, the metal plates themselves. Due to that, if you can indeed form a wormhole from the Casimir effect (just the fact that it violates energy condition does not guarantee that it can), it is likely to be of extremely small size, due to both the very small negative energy and the fact that it has to be far away enough from the plates themselves.
On a more theoretical side, we also don't know if the Casimir effect is actually of negative energy. All that we know is that in QFT, it is of lower energy than the ground state. Experimentally checking if the energy is indeed negative would require testing gravitational effects, since only those actually care about the absolute energy.