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Electrostatic force with multiple dielectrics
Posted 13 set 2009, 18:10 GMT-4 2 Replies
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I am trying to simulate a capacitive membrane that has both electrodes insulated
with a nitride dielectric layer. In other words, the layers in order are---top
electrode, nitride,air gap,nitride,bottom electrode. I want to deflect the
membrane as a function of applied DC bias. Does anyone know if it is acceptable
to apply an electromagnetic force (or basically, electrostatic force) only at the top electrode (which is an interior
boundary)? Will Comsol automatically account for the nitride and air gap in its
calculations? Or will I need to place forces on each internal layer? I can find no Comsol examples in which multiple dielectrics are placed between moving electrodes, so I just want to ensure that the boundary conditions I set will give me valid results. Thanks in advance.
Mike
with a nitride dielectric layer. In other words, the layers in order are---top
electrode, nitride,air gap,nitride,bottom electrode. I want to deflect the
membrane as a function of applied DC bias. Does anyone know if it is acceptable
to apply an electromagnetic force (or basically, electrostatic force) only at the top electrode (which is an interior
boundary)? Will Comsol automatically account for the nitride and air gap in its
calculations? Or will I need to place forces on each internal layer? I can find no Comsol examples in which multiple dielectrics are placed between moving electrodes, so I just want to ensure that the boundary conditions I set will give me valid results. Thanks in advance.
Mike
2 Replies Last Post 9 nov 2009, 15:40 GMT-5
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Posted:
1 decade ago
Hi,
I have a similar problem two solve. not sure how to.
did by any chance found your answer?
best
K
I have a similar problem two solve. not sure how to.
did by any chance found your answer?
best
K
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Posted:
1 decade ago
Hi all,
I posted this problem a while back but am still unsure if I am setting up the model correctly. I have posted an example model of what I am trying to accomplish. It involves deflection of a membrane due to an electrostatic force. The main difference between this and all of the available Comsol examples (i.e. ale cantilever), is that there are multiple dielectrics in between the two electrodes. Currently, I am only applying the Maxwell Force on the electrode, but I am curious if it should be applied at the intermediate dielectric interfaces as well. The reason I am asking is because the pull-in voltage I calculate using this set-up seems to be larger than what we are experimentally measuring.
I have noticed that some users have reported that an air gap must surround the location at which there is a Maxwell electromagnetic force, is this also the case if only electrostatic forces are of concern? If so, that is most likely my problem. Perhaps another method of calculating this force would be ideal?
I have tried different meshing strategies (finer mesh, square mesh elements, etc.) but don't seem to notice much difference.
Any help would be greatly appreciated. Thanks!
I posted this problem a while back but am still unsure if I am setting up the model correctly. I have posted an example model of what I am trying to accomplish. It involves deflection of a membrane due to an electrostatic force. The main difference between this and all of the available Comsol examples (i.e. ale cantilever), is that there are multiple dielectrics in between the two electrodes. Currently, I am only applying the Maxwell Force on the electrode, but I am curious if it should be applied at the intermediate dielectric interfaces as well. The reason I am asking is because the pull-in voltage I calculate using this set-up seems to be larger than what we are experimentally measuring.
I have noticed that some users have reported that an air gap must surround the location at which there is a Maxwell electromagnetic force, is this also the case if only electrostatic forces are of concern? If so, that is most likely my problem. Perhaps another method of calculating this force would be ideal?
I have tried different meshing strategies (finer mesh, square mesh elements, etc.) but don't seem to notice much difference.
Any help would be greatly appreciated. Thanks!
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