Prescribed displacement and pressure

Hi
I'm a student and one of COMSOL user.
I have problem to apllied pressure (1500Pa) at my structure after prescribed displacement (0.1um).
Because the plane by applying the prescribed displacement is not moved when the pressure is applied.
In other word, the prescribed displacement plane is fixed.
Do you have any other idea not to fix the plane?

I am hopfully want to get an idea.

thanks~