Reducing parasitic effects of actuation and sensing schemes for piezoelectric microelectromechanical resonators

The co-integration of piezoelectric actuation and sensing capabilities on microelectromechanical system-based resonators can be a source of electrical cross-talk that, if not properly taken into account, may dramatically affect the interpretation of the device’s output. In this paper, we identify three parasitic electrical effects pertaining to the most commonly used piezoelectric actuation and sensing schemes. To further investigate the impact of such parasitic effects, microcantilevers, bridges and membranes integrating a layer of sol–gel lead zirconate titanate (PZT) were fabricated and electrically characterized. Experimental results on the resonant characteristics were compared with simulations of the studied resonators’ equivalent electrical models. Methods for reducing the design-dependent parasitic electrical effects such as mutual capacitances of less than 10 fF, electrical wiring or static capacitance mismatches of less than 20% of the integrated piezoelectric films are discussed.

Microresonators based of cantilevers with piezoelectric actuation/sensing capabilities and the impact of the parasitic effects management strategy on their dynamic behavior.Figure optionsDownload as PowerPoint slideHighlights
► MEMS integrating sol–gel PZT are fabricated and electrically characterized.
► Three major parasitic electrical effects are identified.
► Dynamic experimental results are compared with behavioral simulations.
► Effects of electrical wiring, mutual and static capacitances presence are suppressed.