Predictive Modelling Approach for a Piezoelectric Bistable Energy Harvester Architecture

The goal of this paper is to present a new lumped model dedicated to Piezoelectric Bistable Energy Harvesters (or PBEHs). Such ambient vibration energy converters are interesting for their broadband frequency response. The PBEH architecture of interest in this paper uses post-buckled beams to create bistability, as well as two Amplified Piezoelectric Actuators (or APAs); one for energy harvesting and another to tune the buckling level. The proposed model provides information on how the beams’ axial stiffness and tuning APA affect the performance and feasibility of the PBEH, which is lacking in literature. The lumped model is first formulated based on the Euler-Lagrange equations and then validated experimentally using a PBEH prototype. It is shown that the relative error between the predicted and measured characteristics and responses of the PBEH remains inferior to 10%. Moreover, the prototype presented produces around 4mW at 4m/s
²
with 22 % relative bandwidth.