# Using Casimir force as a thruster

In quantum mechanics, there is a phenomenon called the 'Casimir effect'. As two metal plates have a very small distance, the plates work as a potential well, causing limited wave function between the plates while outside doesn't. As a result, two plates have a attraction force. (In some case it could be repulsive but that another story.) In this case we can assume that the plate works as infinite potential. But what if one of the plates are not infinite potential wall? Would sum of Casimir force be non-zero quantity?

For example, let's assume that potential is as follows.

$$V(x<0)=0$$

$$V(0

$$V(a

$$V(b

$$V(c

What happens?

• I don't know about your supposed effect, but Casimir pressure is very tiny,- $$P_C = -1.3 \times 10^{-27} [J \cdot m] ~d^{-4}$$. So to be able to extract negative pressure comparable to $1 atm$, one needs to bring plates at a distance comparable to extreme ultraviolet photon wavelength. But the bigger the plates, the greater risk of instabilities and distance irregularities, so keeping steady and uniform force will be a problem anyway. Commented Oct 8, 2020 at 21:04