Energy scavenging from a rotating gear using an impact type piezoelectric mems scavenger

A device for energy harvesting from an impact by using a piezoelectric MEMS harvester comprising at least a gear (1) driven by an inertial mass system and a piezoelectric transducer (2) located over the gear in order to keep the system as compact as possible wherein the piezoelectric transducer, such as a cantilever structure, is coupled to the inertial mass system through a tip (3) at the free end of the cantilever so that when the gear rotates, the piezoelectric cantilever is set into motion by the impact between the gear teeth (4) and the tip of cantilever. On the other hand, the piezoelectric cantilever can be set into motion using locked and released of the tip using the gear. In this matter, the tip and gear shape need to be optimized. Moreover, the frictionless coating of the tip using SiC or diamond would be taken into account in order to improve the efficiency of the systems.

Multiphysics finite element model of a frequency-amplifying piezoelectric energy harvester with impact coupling for low-frequency vibrations

Danick Briand, Nico de Rooij, Pattanaphong Janphuang, Robert Andrew Lockhart, Andres Felipe Vasquez Quintero

This paper presents experimentally-verified multiphysics finite element model of a wideband vibration energy harvester with impact coupling, which operates on the principle of frequency up-conversion: under low-frequency harmonic base excitation a cantilever-type resonator (with resonant frequency of 18.8 Hz) impacts a high-frequency piezoelectric cantilever, which starts freely vibrate at its resonant frequency of 374 Hz. Such input frequency amplification enables efficient power generation under low-frequency ambient excitations. The model was implemented in COMSOL and the contact between the cantilevers was formulated by using a nonlinear viscoelastic model. Reported results of dynamical and electrical testing of the fabricated vibration energy harvester confirm the accuracy of the model as well as reveal some operational characteristics of the device under varying impact and excitation conditions.

Iop Publishing Ltd2013

Harvesting Energy From a Rotating Gear Using an AFM-Like MEMS Piezoelectric Frequency Up-Converting Energy Harvester

Danick Briand, Nico de Rooij, Simon Nessim Henein, Don Isarakorn, Pattanaphong Janphuang, Robert Andrew Lockhart

This paper presents an analytical and experimental study of a compact configuration to harvest energy from a rotating gear using piezoelectric microelectromechanical system harvesters. The reported configuration realizes a contact-type frequency up-conversion mechanism in order to generate useful electrical energy. The up-conversion mechanism was achieved using an atomic force microscope (AFM)-like piezoelectric cantilever plucked by the teeth of the rotating gear that could be eventually driven by an oscillating mass. This paper describes relevant design guidelines for harvesting energy from the low-frequency mechanical movement of a rotating gear through analytical modeling and finite element method (FEM) simulation followed by experimental validation. Different harvester configurations are investigated to identify the optimal configuration in terms of the output energy and energy conversion efficiency. The latter results are reported for the first time because of the implementation of an original concept based on the coupling of the harvester with a rotational flywheel. The experimental results reveal that free vibrations of the harvester after plucking contribute significantly to the output energy and efficiency. By adding a proof mass, the efficiency of the system can be greatly improved. For plucking speeds between 3 and 19 r/s, average output powers in the order of tens of microwatts were obtained for continuous plucking. By combining interaction energy, friction, and energy absorption, between the harvester and inertial mass, the maximum efficiency of the impact piezoelectric harvesters was found to be 1.4%. The efficiency results obtained were compared with the noncontact magnetic plucking approach further demonstrating the potential of our concept. Finally, different tip-gear materials combinations were evaluated showing the importance of their nature on the reliability of the presented configuration.

Ieee-Inst Electrical Electronics Engineers Inc2015

Harvesting Energy From a Rotating Gear Using an AFM-Like MEMS Piezoelectric Frequency Up-Converting Energy Harvester

Danick Briand, Nico de Rooij, Simon Nessim Henein, Don Isarakorn, Pattanaphong Janphuang, Robert Andrew Lockhart

Ieee-Inst Electrical Electronics Engineers Inc2015