PMUT array modelling

Please login with a confirmed email address before reporting spam

Hi folks, I am trying to model displacement of PMUT array. Structure of model includes Sillicon on insulator wafer (SOI), Pt bottom electrode, 1.5um thick piezoelectric material (PZT-8) layer and top electrode. Part of SOI substrate removed (trenches etched from the bottom part to release PMUT elements). Thin layer of Si left below PZT. (akka unimorph with fixed edges). I have experimental data showing increased deflection within released part of PMUT (Etched trench has long oval shape, displacement pattern looks like half of ellipsoid). I created model in Comsol. Applied +5V to top electrode and ground to bottom electrode. Used this example as a reference: https://www.comsol.com/paper/modeling-and-analysis-of-thermal-bimorph-using-comsol-multiphysics-15585

I applied fixed constrained to entire substrate body, in this case displacement pattern look uniform and very small. I also tried to ally fixed constraint to outer boundary of substrate. in this case I see huge deformation of substrate that I don't see on experiment. Here is my model: https://drive.google.com/file/d/1hVWu5MwrB_JuRiNUaEuc152skwUdYRWK/view?usp=sharing

Could you please help with defining proper boundary conditions?

Thank you very much!

Stanislav



0 Replies Last Post 26.08.2024, 13:51 GMT-4
COMSOL Moderator

Hello Stanislav Udovenko

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Reply

Please read the discussion forum rules before posting.

Please log in to post a reply.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.