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Hello Shakti Tripathy

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Hi
I am trying to mudle a cantilever with actuated electrostaically , so could you please send me a tutorial video or written version to know how use the esctrostic field to actuating the cantilever.


alll the best

Hi

I'm working with the same problem as you, I wonder if you have solved this.
If so,please let me know. Would you please show me some direction about
tutorials/models ?

I would appreciate your help very much.

I think the issue is this example is really too complicated for optimal benefit. A super-simple electrostatically actuated contact relay would be very useful.

Hi

the MEMS cantilever example is rather simple, so long one remain within the linear regime, but once one goes above the "pull-in" Voltage the non-linearity makes the solving process more tricky and it requires some tweaking, no ?

It's a good example to understand the frames: material and spatial in Solid, and the moving ALE mesh for the deforming air

If one take it in three steps, solved independently, before adding next physics:
1) cantilever alone Solid (I.e. eigenfrequency, + static with a boundary load)
2) cantilever with air box around deformed via ALE
3) add ES across the air domain

--
Good luck
Ivar

Thanks! This is indeed a very simple example, and it works to the pull-in point, when not surprisingly it fails due to metastability (or no solution at all) but the case I'm interested in is where there's a gate terminal and a separate contact terminal, the cantilever coming into contact with the contact terminal before the pull-in point is reached.

So in this example I reduced the thickness of the cantilever from 2 to 1 micrometer, eliminated the fixed constraint on the right (now the cantilever is supported on only one side), and created a little "contact" of polysilicon which, like the cantilever, is also at zero volts, and so there is no electrostatic force between the cantilever arm and the contact. The bottom boundary of the contact is constrained to prevent it from moving. I defined the contact as linear elastic material and defined a contact pair, on one side the lower boundary of the arm, on the other side the boundaries of contact rectangle. I then defined a default (electromechanical module) contact with the contact pair. This should result in the cantilever getting anchored on two rather than one side when the deflection is sufficient to bring these boundaries into contact.

This works up until contact, then it fails to converge. Here's a screen grab showing Von Mises stress immediately before contact. No stress at the eventual contact point = no contact yet; there's still a small gap:

i.imgur.com/rKmU59E.png

This is, I think, a fairly conventional electrostatically actuated micromechanical relay application, and it would be nice to see it work. Note this DOES work if instead of electrostatic actuation I used a fixed boundary load: then it comes into contact with the switch and stops, using the solid mechanics module and no air. I think perhaps the problem is the moving mesh in the air collapsing, or else it can't handle a gap going to zero even when the boundary condition on both sides is the same potential (0/0).

Any suggestions?