Shell element in squeeze film analysis of MEMS?

Hi!

I'm doing the analysis of squeeze film effect on MEMS devices. Squeeze film analysis simulates the effect of fluid in small gaps between fixed surface and structure moving perpendicular to the surfaces.

Currently, I modeled the moving structure with the SOLID186 element. I overlaying the FLUID136 element on the below surface of SOLID186 to model the fluid domain. Then I used the FLUID138 element to model the pressure drop through holes in moving structure.

But now, I try to model the moving structure by using the SHELL element. But I have got some problem when to model with the FLUID136 and FLUID138 element.

Is it possible to using the shell element? Or you can give me any comment about that.

Thanks in advance.