Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

capacitive pressure sensor

Please login with a confirmed email address before reporting spam

I'm trying to simulate a parallel-plate capacitive pressure sensor. The plates are fixed along the edges, but the top plate can deflect under pressure; thus the capacitance changes.

I am using electrostatics and solid mechanics physics.The problem is, in order to compute the capacitance, I have to add air surrounding and also in between the plates. But air doesn't work in solid mechanics physics, as Young's modulus and poisson's ratio are required. And in fact, it is only vacuum between the parallel plates.

What should I do?
Thank you!

2 Replies Last Post 29 juin 2012, 16:02 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 29 juin 2012, 15:12 UTC−4
Hi

Indeed air is not a structural material, although it is possible to cheat a bit and make air a soft material, hence to get the mesh to deform due to the true structural material deformation, but it's by far cleaner to use the ALE (first) then to have the structural deformation deform the air mesh, and analyse the ES on the ALE deformed mesh.

This is already what is put into the EMI physics, everything "pre-cooked" so that is the shortest way. There are a few examples by the model library, take a look and do a few similar examples first

--
Good luck
Ivar
Hi Indeed air is not a structural material, although it is possible to cheat a bit and make air a soft material, hence to get the mesh to deform due to the true structural material deformation, but it's by far cleaner to use the ALE (first) then to have the structural deformation deform the air mesh, and analyse the ES on the ALE deformed mesh. This is already what is put into the EMI physics, everything "pre-cooked" so that is the shortest way. There are a few examples by the model library, take a look and do a few similar examples first -- Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 29 juin 2012, 16:02 UTC−4
Thank you!
Thank you!

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.