# 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?

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.