Piezoelectric modal sensors/actuators based on microplates applying surface electrode patterning

We demonstrate an advanced design procedure to fabricate resonators based on flexible plates with piezoelectric films. Two design strategies are considered: i) optimized response (actuation or sensing) in a given mode; ii) implementation of a modal transducer by filtering specific modes. Sensors/actuators were designed by optimizing the surface electrode shape in both dimensions. A numerical finite element procedure, which considers the effective surface electrode covering the piezoelectric film as a binary function on each element, has been developed. Microcantilevers and microbridges were fabricated and their modal response characterized by laser Doppler vibrometry. Our calculations allowed us to predict, for a given mode in a plate with arbitrary boundary condition, the top electrode layout with higher displacement in resonance than any other electrode design for the same structure. Our experiments show that the implemented designs can suppress the contributions of different modes simply by shaping the surface electrodes.