Hi, folk~ I fabricated bimorph piezoelectric shear stress sensors. When air flow applied, there were resonant frequency shifts to left side (decreasing) and impedance decrement in resonant frequency as well . So even though I am suspecting that kinds of results as because of damping effect (from shear force) on the Piezo sensor, I am not sure my hypothesis would be correct and how do prove my idea with electromechanical (or mathematical) modeling. If you guys have another ideas or something helpful comments, please let me know..HELP ME PLZ... Thank you in advance.