Discussion Forum

Hello everyone,

First of all, I'd like to say that I am quite new in COMSOL, so please forgive me if my question is too basic.

I am trying to obtain the dielectrophoretic (DEP) potential generated by an inhomogenous surface charge distribution (Sigma) in a rectangular plate at some height from the plate. To do that, I need to evaluate a set of integrals for each component of the electric field, as the DEP potential is proportional to E^2. I have defined a Component Coupling => Integration in the spatial frame (intop1) to evaluate this components. As an example, I have defined the x-component of the electric field as:

Ex=intop1(Sigma*(x-dest(x))/((x-dest(x))^2+(y-dest(y))^2+(height)^2)^(3/2))

I evaluate this expression in two domains. The first one overlaps with the charged plate while the second one is a kind of frame around it (so I can study the potential away from the plate). The result is very different in each domain (I attach an image).

I think the problem comes from some indetermination (1/0 or 0/0) in the integral, as I have obtained simmilar results when I calculate the electric field at height =0.

Is there another way to calculate the distance? Can I just use the Electric Field of the AC/DC module although I am not interested in the other variables? How?

Thank you very much!