Discussion Forum

Hi all,

I have posted on here previously concerning the best way to model the electrostatic force between 2 electrodes that are separated by dielectric - air gap - dielectric. Up to now, I have been using the Maxwell Tensor since it is the easiest, but I am not certain it is giving valid results. The fact that it typically requires the boundary of applied force to be surrounded by air prevents me from applying the force on the electrode, which seems the more logical location for it.

I have contacted Comsol support and they believe I can simply integrate the Tensor over the air domain, and apply the negative of that resultant force to the surface of the dielectric that surrounds the air gap. Using this method, my results seem the most reasonable, but still are sometimes quite different then what I would expect.

Thus, I am wondering if perhaps the virtual work method would be better. Does anyone have experience with it? Does it require the boundary at which the force is applied to be surrounded by air, similar to the Maxwell Tensor method?

Other suggestions/comments?

Thanks,

Mike