A piezoelectric vibration based generator for wireless electronics

Enabling technologies for wireless sensor networks have gained considerable attention in research communities over the past few years. It is highly desirable, even necessary in certain situations, for wireless sensor nodes to be self-powered. With this goal in mind, a vibration based piezoelectric generator has been developed as an enabling technology for wireless sensor networks. The focus of this paper is to discuss the modeling, design, and optimization of a piezoelectric generator based on a two-layer bending element. An analytical model of the generator has been developed and validated. In addition to providing intuitive design insight, the model has been used as the basis for design optimization. Designs of 1 cm³ in size generated using the model have demonstrated a power output of 375 µW from a vibration source of 2.5 m s⁻² at 120 Hz. Furthermore, a 1 cm³ generator has been used to power a custom designed 1.9 GHz radio transmitter from the same vibration source.