Capacitance between two adjacent long thin plates

1. Dec 4, 2011

theHermes5

Hi.

I am working on a project for the design of a capacitive sensor. In order to do that, I am required to compute capacitance using a simulation software like COMSOL. As I want to compare my simulation results with the theoretical results, I would like to know the formula to be used for the capacitance.

It is not C= epsilon0*epsilonR*A/d as the plates are long and thin like this:

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I hope this diagram makes sense. ( Consider the plates to be of large length ( in the order of 0.1mm) and very small width ( in the order of 0.005mm). I want to calculated capacitance between these two plates.

Can you help me with the formula?

Thanks for your help.

Last edited: Dec 4, 2011
2. Dec 4, 2011

marcusl

Your drawing isn't clear. Are the "plates" supposed to be coplanar and end to end (like a ribbon that, halfway down its length, has been cut across to make two shorter ribbons)? If so, there is no analytic formula for capacitance.

3. Dec 4, 2011

theHermes5

The plates are like as shown in attachment.

Now, can you help me with the capacitance formula?

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4. Dec 4, 2011

marcusl

I don't know of any analytic formulas for this case.