mesh rectangular box with 0.1mm diameter holes in gambit
 

Dear all:
I want to mesh a rectangular box with 0.1mm diameter holes at the bottom face. (The holes are the boundaries for velocity inlet) . But because of small diameter of the holes, the quality of meshes in the bottom face is not suitable (just 2 or 1 mesh for each hole). If i decrease the interval size of meshes, number of meshes increase illogical. Do you have any idea for mesh or design this box?
Is it possible to divide the volume in 2 parts in mesh with specified condition at interval size and type?