Design, Fabrication and Characterization of a Piezoelectric Microgenerator Including a Power Management Circuit

We report in this paper the design, fabrication and experimental characterization of a piezoelectric MEMS microgenerator. This device scavenges the energy of ambient mechanical vibrations characterized by frequencies in the range of 1 kHz. This component is made with Aluminum Nitride thin film deposited with a CMOS compatible process. Moreover we analyze two possible solutions for the signal rectification: a discrete doubler-rectifier and a full custom power management circuit. The ASIC developed for this application takes advantage of diodes with very low threshold voltage and therefore allows the conversion of extremely low input voltages corresponding to very weak input accelerations. The volume of the proposed generator is inferior to 1mm3 and the generated powers are in the range of 1$\mu$W. This system is intended to supply power to autonomous wireless sensor nodes.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Top-Down Behavioral Modeling Methodology of a Piezoelectric Microgenerator For Integrated Power Harvesting Systems

In this study, we developed a top/down methodology for behavioral and structural modeling of multi-domain microsystems. Then, we validated this methodology through a study case : a piezoelectric microgenerator. We also proved the effectiveness of VHDL-AMS language not only for modeling in behavioral and structural levels but also in writing physical models that can predict the experimental results. Finally, we validated these models by presenting and discussing simulations results.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Hybridization of Magnetism and Piezoelectricity for an Energy Scavenger based on Temporal Variation of Temperature

Autonomous microsystems are confronted today to a major challenge : the one of energy supply. Energy scavenging, i.e. collecting energy from the ambient environment has been developed to answer this problematic. Various sources have already been successfully used (solar, vibration). This article presents temporal variations of temperature as a new source of exploitable energy. A brief review will take place at the beginning, exposing the different approaches used in the past. Then we will focus our attention on hybridization of magnetism and piezoelectricity. A new kind of thermal generator is proposed and a preliminary model is exposed. Conclusions will be drawn on the suitability of this prototype and the improvements that are needed to increase its potential.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

A complete study of electroactive polymers for energy scavenging: modelling and experiments

Recent progresses in ultra low power microelectronics propelled the development of several microsensors and particularly the self powered microsystems (SPMS). One of their limitations is their size and their autonomy due to short lifetime of the batteries available on the market. To ensure their ecological energetic autonomy, a promising alternative is to scavenge the ambient energy such as the mechanical one. Nowadays, few microgenerators operate at low frequency. They are often rigid structures that can perturb the application or the environment; none of them are perfectly flexible. Thus, our objective is to create a flexible, non-intrusive scavenger using electroactive polymers. The goal of this work is to design a generator which can provide typically 100 ?W to supply a low consumption system. We report in this paper an analytical model which predicts the energy produced by a simple electroactive membrane, and some promising experimental results.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Non Linear Techniques for Increasing Harvesting Energy from Piezoelectric and Electromagnetic Micro-Power-Generators

Non-linear techniques are used to optimize the harvested energy from piezoelectric and electromagnetic generators. This paper introduces an analytical study for the voltage amplification obtained from these techniques. The analytical study is experimentally validated using a macro model of piezoelectric generator. Moreover, the integration influences on these techniques is studied. Through all the obtained results, a suitable structure for autonomous microsystems is proposed.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Non linear techniques for increasing harvesting energy from piezoelectric and electromagnetic micro-power-generators

Non-linear techniques are used to optimize the harvested energy from piezoelectric and electromagnetic generators. This paper introduces an analytical study for the voltage amplification obtained from these techniques. The analytical study is experimentally validated using a macro model of piezoelectric generator. Moreover, the integration influences on these techniques is studied. Through all the obtained results, a suitable structure for autonomous microsystems is proposed

PiezoMEMS for energy harvesting and for haptic devices

National audienc

Coupled multiphysics nite element model and experimental testing of a thermo-magnetically triggered piezoelectric generator

International audienceThis paper deals with the coupled multiphysics finite element modeling and the experimental testing of a thermo-magnetically triggered piezoelectric generator. The model presented here, which has been developed in ANSYS software and experimentally validated, promotes a better understanding of the dynamic behavior of proposed generator. Special attention was put into the coupled multiphysics interactions, for instance, the thermal-dependent demagnetization of soft magnetic material, the piezoelectric transduction and the output power.In order to characterize the power generator, many finite element simulations were conducted, included modal and transient analysis. To verify the effectiveness of the model, a prototype was built and tested. The findings thus obtained were compared with simulation results. Obtained results describe for the first time a fully coupled model of an innovative approach for thermomagnetic energy harvesting. Moreover, the total volume of our harvester (length x width x height: 20 x 4 x 2 mm) is 85 times lower than that of previous experimental harvester

Modeling of Piezoelectric MEMS Vibration Energy

International audienc

Conception et optimisation d’un micro-générateur piézoélectrique à déclenchement thermomagnétique pour des capteurs autonomes

National audienceCe travail porte sur la thématique de la récupération de l’énergie par transduction piézoélectrique. L’objectif général est d’assurer l’autonomie, en alimentation électrique, des nœuds d’un réseau de capteurs sans fil. Dans cet article nous décrivons la conception d’un micro-générateur piézoélectrique optimisé à travers ses dimensions à l’aide d’un modèle en éléments finis. Ce modèle est validé expérimentalement.Le système étudié est une structure constituée d’une poutre encastrée-libre munie de deux patchs piézoélectriques collés sur ses deux faces longitudinales. Nous avons modélisé ce dispositif en 3D sur ANSYS®, afin de le caractériser en régime statique et dynamique. Cette étude a été validée par l’intermédiaire d’un modèle analytique, qui se base sur les hypothèses d’Euler-Bernoulli pour les poutres en flexion. Cette technique nous a permis de maximiser la réponse en énergie du dispositif via les dimensions des patchs piézoélectriques. Pour mettre en valeur l’effet de ce procédé, une comparaison des performances du micro-générateur, avant et après l’optimisation, est établie. L’apport de ce travail réside dans l’approche du fonctionnement du micro générateur, à déclenchement thermomagnétique grâce à l’hybridation piézo-magnétique et dans la méthodologie d’optimisation et de conception du générateur