Reconstructing the Model of a Nonlinear MEMS Structure by the Example of a Piezoelectric Resonant Energy Harvester

Microelectromechanical systems contain mechanical elements coupled with conditioning electronics that control and process the signal generated by the mechanical component. These systems are miniature and can be easily integrated on one chip, which explains the enormous popularity of MEMS. The applications of MEMS began with environmental sensors and have grown to encompass RF and optical applications along with energy harvesting. Because of their mixed-domain nature, the design of conditioning electronics relies on accurate models of the mechanical component. As an additional requirement, the model must be simple enough and be compatible with common circuit simulation tools. The latter requirement may be particularly difficult to achieve due to the fact that most of modern MEMS structures are quite complex and often nonlinear. In this conference contribution, we describe the methodology of building a model of a nonlinear MEMS resonator using the conventional modelling approach and then using an improved model together with an optimisation technique on the basis of the circuit simulator PAN.