Discussion Forum

Hi, I'm a beginner in COMSOL and I'm trying to simulate a nanoimprinting lithography process. The sample is made by the following consecutive layers: Silicon1 (0.53 x 25 x 25 mm), Silicon2 (0.01 x 20 x 20), PMMA (0.5 x 21 x 21), Silicon3 (0.53 x 21 x 21), teflon (1 x 21.5 x 21.5 mm). All this is sandwiched between two plates of a pressing machine (which are not included in the geometry). Now I need to tell COMSOL that I want an uniform pressure of 4MPa on the PMMA layer surface below Silicon2 layer (so a uniform pressure on the central 20x20mm area of the PMMA) so that I can see which pressure distribution I have on the Silicon1 surface attached to the plate (which will be used to then modify the Silicon1 surface). I've tried appling boundary load pressure, which works, but the results show that the pressure is uniform but of 0Pa and not 4MPa. I've tried also defining the load as force per unit area but I still get the same result. Is there any other way in which I can tell the program to apply a uniform pressure? Thanks.