Curved flexoelectric and piezoelectric micro-beams for nonlinear vibration analysis of energy harvesting

Micro/nano-scale energy harvester is an enabling technology to provide sustained energy solutions for various micro/nano-electromechanical devices, this has attracted intensive research interests in both academia and industry in the past decades. Exploring various design possibilities for energy harvesters in terms of geometry, topology, materials as well as harnessing the interesting nonlinear responses have the potential to break the current limit of energy harvesters in terms of energy efficiency and power density. While most designs were limited to straight beams, in this work, we demonstrate that the nonlinear vibration of energy harvester is significantly affected by curved shapes and we show the possibility of improving its performance by tuning the structural curvature. By developing a couple stress-based piezo-flexoelectric curved beam model and using the multiple time scale method for the nonlinear frequency response analysis, the effect of structural curvature in the nanoscale arc-shaped beam is quantitatively evaluated.