On the optimization and performances of a compact piezoelectric impact MEMS energy harvester

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Two-stage AC/DC converters are typically realized with an Active Front End (AFE) unit followed by an isolated DC/DC unit. In single-phase systems, the AFE unit introduces a second-order harmonic ripple to the system, which can undesirably propagate to the output voltage. If the DC/DC is realized with a Series-Resonant Converter (SRC), the propagation of the second-order harmonic ripple can be neutralized by controlling its switching frequency. The operating principle and steady-state performances of this ac

As can be seen from the large number of videos of home-made dielectric elastomer actuators (DEAs) on YouTube, getting started making DEAs is straightforward and can be done at low cost. This chapter provides information on making two types of basic dielectric elastomer actuators, as well as detailed information on using DE for energy harvesting (converting mechanical energy into electrical energy).

The key element of a SAW device is the piezoelectric material that allows conversion between electrical and mechanical energy. Lithium niobate is an appealing material as it could potentially provide high efficient SAW devices. This material is strongly anisotropic, thus, all the properties of the material are dependent of the orientation on the plane of the device and on the chosen piezoelectric layer cut. An analytical model is built to predict how the electromechanical coupling varies depending on cut an

Within the goal of reducing greenhouse gas emissions and supplying sustainable energy, complex integrated energy conversion systems have to be designed by taking into account thermodynamic, economic and environmental considerations simultaneously. The process performance highly depends on the quality of the process integration and on the energy conversion, in particular, on how the heat requirements are balanced and how the combined heat and power generation is integrated. In chemical processes, the heat re

The miniaturized solid oxide fuel cells (µ-SOFCs) has become an intensively studied device for portable power generation technology due to its wide choice of hydrocarbon fuels, its high energy density and its great operation efficiency. It is being considered as a battery replacement [1]. The µ-SOFC system, which aims to provide electrical energy (≤ 10 W) at an operating temperature of ca. 550°C, consists of a fuel cell unit for the electrochemical conversion [2-3]; a fuel processing unit for the thermal st

This paper presents an approach to design a contactless energy-transfer system to supply desktop computer peripherals. Energy is transferred using coreless transformers from an array of primary coils (placed on a table) to one or several secondary coils (placed under the peripheral). Knowing the geometrical structure of the coils of a coreless transformer, accurate calculations allow predicting the power that can be transferred to a load. By applying these calculations to one basic energy-transfer cell, it

Bulk PZT ceramics provide high electromechanical coupling (k) which is desirable for piezoelectric energy harvesters since the energy transformed from a mechanical agitation into an electrical output is proportional to k2 [1-2]. However, piezoelectric cantilever-based energy harvesters using bulk PZT require a bonding layer to couple the thick PZT sheet to the elastic layer substrate, typically silicon. We present the characteristics and performance of vibration energy harvesters comparing three different b

Piezoelectric motors are particular motors converting electrical energy into mechanical movement, based on the inverse piezoelectric effect. Piezoelectric material, when electrical field applied, produces acoustic or ultrasonic vibrations. These vibrations can be used to create a linear or rotary motion. The piezoelectric material has to be excited at its resonance frequency to actuate the rotor. In a first step of this master project, a new rotor for a standing wave ultrasonic motor with cylindrical actuat

The proposed project addresses the optimal integration of a steam reforming process in a gas turbine power plant. In this configuration, the H2 produced by the way of natural gas fuel reforming is burned in the "clean" gas turbine and the upstream CO2 is removed and sequestrated. The goals of the project are: - to integrate the steam reforming process in the gas turbine power plant - to perform a thermo-economic optimisation to relate the generating cost of electricity with the electrical power output of th

As our awareness of the dangers of global climate change grows, the development of new renewable energy technologies is of primary importance in the effort to reduce emissions of carbon dioxide and other greenhouse gases. Rapid increases in the price of oil and worries about the stability and security of the extraction of fossil fuels have lead to renewed interest in the development of local energy sources, thereby reducing dependence on foreign sources. Amid the plethora of option available, one of the mor

In the frame of development of the ITER electron cyclotron wave (ECW) system, a two MW CW coaxial cavity gyrotron will be developed during the Sixth Framework Program (2003-2006). Such development relies on the availability of a test stand capable of providing the electrical energy and cooling capacity. This test stand will possibly be used, in a later stage, for the component test of the ITER ECW system. This paper will first present the main parameters of this new coaxial gyrotron. Then we describe the te

For a general class of constant-energy trellis-coded modulation schemes with

2^{\nu}

states, necessary and sufficient conditions to guarantee that a maximum-likelihood sequence estimator can decode each symbol with a fixed delay of

\nu

symbols are derived. Additive white Gaussian noise is assumed. {MSK} is a special case that belongs to the family of modulation schemes with

\nu=1

. It is shown that when these conditions are met, the minimum squared Euclidean distance is upper bounded by

4E_s

, where $

Piezoelectric response nonlinearity is approached using the Preisach description of hysteretic systems as collection of distributed bistable units. The Preisach model and its recent physical interpretation in terms of moving domain wall in a stochastically described pinning field are reviewed. It is shown that such an approach can effectively render not only the piezoelectric coefficient field dependences but also the field-response hysteresis, especially in the well-known case of linear piezoelectric field

The transmission of energy or signals to a rotating device is generally carried out by systems with sliding contacts. This technology, apparently simple, generates serious nuisance such as abrasion of the elements in contact, electric noises and requires a relatively important volume. These devices, of limited life cycle, generally request quite expensive maintenance. The transmission of energy or information by induction seems then an interesting alternative to this technology. In fact, the constant evolut

The aim of this letter is to present a universal power quality conditioning system (UPQS) named after unified power quality conditioner (UPQC), which is extended by adding a shunt active filter at the load side. Its main purpose is to compensate for supply voltage and load current imperfections, such as sags, swells, interruptions, imbalance, flicker, harmonics, reactive currents, and current unbalance. Converter and control analysis is presented together with results showing the UPQS modes of operation.

Ultrasonic motors for low electrical power applications are considered for portable devices such as an electronic wristwatch. For the study of a standing wave type motor, a modular approach was proposed, where stators and rotors are added in an assembly step. The mode conversion principle called the 'elastic fin motor' and its extension to an 'elastic force motor' suitable for a flat profile motor are discussed. Fabrication methods and the mechanical response of silicon diaphragms covered by PZT (PbZrxTi1-x

A micro-pump for medical applications is being developed using organometallic derived PZT thin films and silicon micromachining technology. Critical issues include the deposition of 'thick' PZT films (1 to 2 mu m thickness), film processing compatibility with available Si/SixNy/Ta/Pt structures and the establishing of piezoelectric poling parameters. A processing technique for the preparation of thick PZT films is presented. Piezoelectric properties are characterized by both direct method using alternating

On the optimization and performances of a compact piezoelectric impact MEMS energy harvester

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Dynamic Analysis and Control Design of Second-Order Harmonic Active Filters based on Series-Resonant Converters

Dielectric Elastomers as EAPs: How to start experimenting with them

Nano-SAW devices for RFID and sensing applications: study of lithium niobate behavior

The role of process integration techniques in the thermo-economic optimization of energy conversion systems

Development of a low temperature co-fired ceramic fuel processor for the micro-scale solid oxide fuel cell system

Design of a Contactless Energy-Transfer System for Desktop Peripherals

Assembling of Thick PZT Sheet on Silicon for Energy Harvesting Applications

Indirect position control of a piezoelectric motor

Thermo-economic integration of a steam reforming process with CO2 removal for gas turbine power generation.

Evaluation of a Combined Cycle Setup for Solar Tower Power Plants

Design study of a test stand for ITER gyrotron

Bandwidth-Efficient Constant-Energy Trellis-Coded Modulation Schemes with Prescribed Decoding Delay

Preisach modeling of piezoelectric nonlinearity in ferroelectric ceramics

Transmission électromagnétique rotative d'énergie et d'information sans contact

Power quality compensation using universal power quality conditioning system

Flexural-standing-wave elastic force motor using ZnO and PZT thin film on micromachined silicon membranes for wristwatch applications

PZT films for micro-pumps