Can someone please help me understand why my piezoelectric actuator switches polarity at a certain voltage? The below is just positive voltage applied across it, but ~50V it starts to deflect downwards instead of upwards. I understand that this is related to the coercive field and this is a soft PZT so expect some instability in the domain walls, but i was surprised this was happening at such a low applied voltage. Any help in understanding and/or a way to calculate the max voltage before polarity switching based on size/thickness of the piezo? The below shows um deflection on the y axis, at the labelled voltages.
Thanks!
Thanks!
