Energy Autonomous Micro and Nano Systems E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 470

Veröffentlichungsjahr: 2012

Beschreibung

Providing a detailed overview of the fundamentals and latest developments in the field of energy autonomous microsystems, this book delivers an in-depth study of the applications in the fields of health and usage monitoring in aeronautics, medical implants, and home automation, drawing out the main specifications on such systems. Introductory information on photovoltaic, thermal and mechanical energy harvesting, and conversion, is given, along with the latest results in these fields. This book also provides a state of the art of ultra-low power sensor interfaces, digital signal processing and wireless communications. In addition, energy optimizations at the sensor node and sensors network levels are discussed, thus completing this overview.

This book details the challenges and latest techniques available to readers who are interested in this field. A major strength of this book is that the first three chapters are application orientated and thus, by setting the landscape, introduce the technical chapters. There is also a good balance between the technical application, covering all the system-related aspects and, within each chapter, details on the physics, materials and technologies associated with electronics.

Leseprobe

Table of Contents

Introduction. Introduction to Energy Autonomous Micro and Nano Systems and Presentation of Contributions

I.1. Context of energy-autonomous systems and micro-nanosystems

I.2. Sample applications

I.3. Energy harvesting, storage and conversion

I.4. Data acquisition, processing and transmission

I.5. Energy management

I.6. Bibliography

Chapter 1. Sensors at the Core of Building Control

1.1. Introduction

1.2. Sensors in buildings

1.3. New sensor needs

1.4. An example: the HOMES comfort sensor prototype

1.5. Conclusion

1.6. Bibliography

Chapter 2. Toward Energy Autonomous Medical Implants

2.1. Introduction

2.2. Current and potential applications

2.3. Conclusion

2.4. Bibliography

Chapter 3. Energy Autonomous Systems in Aeronautic Applications

3.1. Motivation

3.2. Wireless systems

3.3. Autonomous systems

3.4. Summary

3.5. Bibliography

Chapter 4. Energy Harvesting by Photovoltaic Effect

4.1. Introduction

4.2. Light power available indoors and outdoors

4.3. Photovoltaic cell: physical principle and model

4.4. Comparison between various photovoltaic cell technologies

4.5. Electronic management

4.6. Conclusion

4.7. Bibliography

Chapter 5. Mechanical Energy Harvesting

5.1. Energy-harvesting analysis

5.2. Main sources and conversion principles of mechanical energy

5.3. Harvesting mechanical energy from vibrations

5.4. Mechanical energy harvesting from forces/deformations

5.5. Conclusions and perspectives on mechanical energy harvesting

5.6. Bibliography

Chapter 6. Thermal Energy Harvesting

6.1. General presentation

6.2. Energy harvesting by thermoelectric effect

6.3. Thermoelectric materials

6.4. Technological trends

6.5. Implementation constraints and optimization

6.6. Electronic management of autonomous thermoelectric systems

6.7. Conclusions on thermal energy-harvesting systems

6.8. Bibliography

Chapter 7. Lithium Micro-Batteries

7.1. Development of lithium batteries over 20 years

7.2. The lithium system aiming for strong miniaturization properties

7.3. Bibliography

Chapter 8. Ultra-Low-Power Sensors

8.1. Introduction

8.2. Overview of sensors and their proximity electronics

8.3. Capacitive sensors

8.4. Resistive sensors

8.5. Conclusions

8.6. Bibliography

Chapter 9. Ultra-Low-Power Signal Processing in Autonomous Systems

9.1. Low-power consumption

9.2. Digital signal processors

9.3. Decreasing static power consumption

9.4. Asynchronous architectures

9.5. Error tolerance

9.6. Conclusion

9.7. Bibliography

Chapter 10. Ultra-Low-Power Radio Frequency Communications and Protocols

10.1. Introduction

10.2. Radio frequency and associated restrictions

10.3. Communication standards and protocols

10.4. Components and solutions

10.5. Conclusion

10.6. Bibliography

Chapter 11. Energy Management in an Autonomous Microsystem

11.1. Wireless sensor nodes

11.2. Power supplied by energy recuperators

11.3. Distribution, conversion and energy storage architectures

11.4. Implementing regulators

11.5. Algorithms

11.6. Conclusion

11.7. Bibliography

Chapter 12. Optimizing Energy Efficiency of Sensor Networks

12.1. Introduction

12.2. Optimization methodology

12.3. Energy consumption model

12.4. Hardware optimization

12.5. Software organization and efficient protocols

12.6. Optimizing energy of algorithms

12.7. Conclusion and perspectives

12.8. Bibliography

List of Authors

Index

First published 2012 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:

ISTE Ltd

John Wiley & Sons, Inc.

27–37 St George’s Road

111 River Street

London SW19 4EU

Hoboken, NJ 07030

UK

USA

www.iste.co.uk

www.wiley.com

© ISTE Ltd 2012

The rights of Marc Belleville, Cyril Condemine to be identified as the author of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

Energy autonomous micro and nano systems / edited by Marc Belleville, Cyril Condemine.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-84821-357-9

1. Electric power supplies to apparatus. 2. Low voltage systems. 3. Direct energy conversion. 4. Energy conservation--Equipment and supplies. 5. Nanoelectromechanical systems. I. Belleville, Marc. II. Condemine, Cyril. TK2896.E47 2012 620′.5--dc23

2012012115

British Library Cataloguing-in-Publication Data

A CIP record for this book is available from the British Library

Introduction

Introduction to Energy Autonomous Micro and Nano Systems and Presentation of Contributions1

I.1. Context of energy-autonomous systems and micro-nanosystems

An energy-autonomous system is able to operate, throughout its lifetime, without needing an energy supply other than that naturally available in its environment, which therefore excludes any system linked to the electric grid or which requires battery replacements. A modern energy-autonomous system usually includes sensor(s) or actuators, an energy harvesting and conversion device, to which storage, signal treatment, and wireless communications elements are almost systematically associated.

The oldest autonomous systems can probably be found in watch-making: in the 1760s, James Cox invented a clock with seemingly perpetual motion, which relied on the energy produced by changes in atmospheric pressure [COX 11]. More recently, Jean-Léon Reutter’s Atmos clock, designed to operate for 600 years without human intervention, winds itself up using a gaseous mixture that retracts and dilates at each temperature variation [ATM 11]. Let us finally mention mechanical rotor winding, used in many wristwatches, which relies on the movement of the arm. These first examples show the diversity of available energy sources and the associated conversion techniques. Road signal panels, made autonomous through photovoltaic cells, are another developing application, especially in isolated areas. Another application of these systems is thus linked to the fact that for localization, technical or economic reasons, we cannot link them to a wired communication or supply network. The main applications today are often monitoring (well-being of goods, items, or structures, quality control, etc.) and predictive maintenance. Cost reduction due to cable suppression is another motivation.

In parallel to the development of these “large” autonomous systems, a lot of research on energy-autonomous micro- and nanosystems began in the late 1990s. A team from the University of Berkeley [PIS 11] introduced the now-famous “Smart Dust” concept. Their aim was to design a 1 mm3 device, which would include a sensor, supply, two-way communication link, and a microprocessor. The conjunction of multiple advances, shown below, allowed for the creation of these energy-autonomous micro- and nanosystems and their associated applications.

The evolution of microelectronic technologies toward ever-smaller scales (Moore’s Law) allows us to integrate all of such system’s functions on a single chip: analog, digital signal control and treatment, and radiofrequency communication functions. Similarly, the size and costs of sensors have greatly decreased due to micro- and nanotechnologies, which are also used to manufacture energy microtransducers. The same trend was observed for batteries. All of these factors, when brought together and synthesized through the most recent manufacturing techniques (such as 3D stacking [ECU 11]), paves the way toward very small dimensions for our full system.

For a micro- or nano-scale energy-autonomous system to be realistically feasible its energy consumption must be less than its supply. However, the amount of energy that can be harvested and stored is directly linked to the size of the device: very small sizes are therefore very unfavorable to the microsystem’s energy supply. However, the conjunction of continuous improvements in yields, for energy harvesting, conversion and storage, and in the power consumption reduction of digital, analog, and radiofrequency circuits have made these autonomous microsystems possible. This trend is illustrated in Figure I.1 (with all curves normalized).

Figure I.1.Evolution of the energy performances of a sensor node’s elements

Battery power density (whether by unit mass or unit volume) increases by about 10% every year [PIL 04]. Similarly, the efficiency of electronic components increases: for digital signal processors, the dissipated power is halved every 18 months (Gene’s law [FRA 00]); in a few years, radio transmitters have seen their efficiency go from 100 nJ per transmitted bit to under 3 nJ/bit in the most advanced publications1; sensor interfaces have also improved significantly, as shown here through a figure of merit on capacitive sensors2.

This book thus seeks to give the reader a state-of-the-art and perspectives of this developing field of research, by tackling examples of some applications and detailing each implementable subset in depth. This subject was the object of a European-level working group [BEL 09] to which some of the authors of this book have contributed, directly or indirectly.

I.2. Sample applications

The first part of this book aims to describe, by presenting three very different fields, the applications considered today and possible in the medium term, the environments in which the energy-autonomous microsystems would be deployed, and the specifications which could be required. Through these examples, the reader can note the very large situation diversity, each of which could lead to different technical choices.

The first chapter tackles building control. It was written by Gilles Chabanis, Laurent Chiesi, Hynek Raisigel, Isabelle Ressejac, and Véronique Boutin from Schneider Electric. These authors present two new sensor applications: an optimized energy consumption control based on the knowledge of the occupation context, and physical comfort parameters and an air quality control within buildings through monitoring pollutant concentrations. To conclude this chapter, the authors show how a wireless autonomous sensor integrating many physical measurements and a digital data analysis core can be realized.

The second chapter, written by Raymond Campagnolo from CEA-Leti and Daneil Kroiss from the SORIN group, addresses the energetic autonomy of implantable medical devices. If there ever was a field in which the greatest autonomy is desired, this is it: indeed, greater autonomy limits the need for surgery. The authors make a complete inventory of implantable medical devices, taking care each time of making a complete energetic assessment. This assessment allows them to identify the applications which could potentially become energyautonomous. They also describe the first attempts at energy recovery from the human body, based on heart motion or glucose pumps.

The third chapter tackles energy-autonomous systems in aeronautical applications. It was written by Thomas Becker, Jirka Klaue, and Martin Kluge from EADS Innovation Works. The authors begin by presenting future applications for energy-autonomous systems in aeronautics, in the field of maintenance assistance, navigational personnel assistance, and flight test instrumentation. They then detail the problems inherent with wireless communications on a plane, and their solution. The chapter concludes with some examples of aircraft energy harvesting developed by this team: vibrational energy in a helicopter and thermal energy in a plane.

I.3. Energy harvesting, storage and conversion

The second part of this book covers all the aspects linked to supplying energy to an autonomous microsystem. First, this environmental energy must be harvested. It can take a number of forms: mechanical, radiated, thermal, chemical, etc. Furthermore, energy available at a transducer’s outlet can take many varied forms: from a few millivolts for a thermo-element to a few hundred volts in vibrational systems, for example. A second challenge is thus to convert this harvested energy into the voltages more suitable for electronics. Finally, as energy sources are often intermittent and hard to predict by nature, storing this energy is necessary to form a buffer and allow for continuous operation.

Energy harvesting through the photovoltaic effect is detailed in the fourth chapter, by Emmanuelle Rouvière and Simon Perraud from CEA Liten. First, they discuss light power, which is linked to spectral radiation and available in both indoor and out-of-door environments. The physical principle, characteristics, and modelization of a photovoltaic cell are detailed, and the various photovoltaic cell technologies are compared. Cyril Condemine and Guy Waltisberger from CEA Leti conclude this chapter by introducing the principles of optimal photovoltaic energy conversion.

The fifth chapter, written by Ghislain Despesse, Jean Jacques Chaillout, Sébastien Boisseau, and Claire Jean-Mistral from CEA Leti, tackles the harvesting of mechanical energy. As a preamble, the sources and physical principles of mechanical energy conversion (piezoelectricity, electromagnetism, electrostatics, and electroactive polymers) are introduced. The authors then present the harvesting of vibrational mechanical energy, with a state-of-the-art of piezoelectric, electromagnetic, and electrostatic transducers, with and without electrets. The following section considers mechanical energy recovery from forces and deformations, focusing on the contribution of electroactive polymers.

The recovery of thermal energy is analyzed by Emmanuelle Rouvière and Tristan Caroff from CEA Liten in the sixth chapter. The Seebeck effect that allows the conversion of thermal energy into electrical energy, and is generally implemented, is detailed. Then, a state-of-the-art of the various thermoelectric materials and associated technologies is presented. This section ends with a description of the implementation constraints. Jérôme Willemin, from CEA Leti, concludes this chapter by tackling optimal thermal energy conversion electronics, paying particular attention to the impact of the very weak voltage and high-outlet impedance of thermo-elements.

In the seventh chapter, Raphael Salot, from CEA Liten, talks about energy storage by tackling lithium micro-accumulators. After defining the main characteristics of accumulators and showing their evolution over the past 20 years in terms of both performance and materials, he tackles the problem of strong miniaturization. He first describes the recent progress leading to the creation of mini-batteries. This chapter then ends with a detailed presentation of micro-batteries created using thin-layer technologies, and a discussion of their potential applications, especially in autonomous systems.

I.4. Data acquisition, processing and transmission

An autonomous microsystem must ensure an interface function with the external environment. It thus contains one-or-more sensor, display or actuator elements. These elements require interface electronics (usually an analog front-end followed by some digital signal processing) to format information. Finally, autonomy almost systematically implies a wireless communication system to exchange information with a distant system. Minimizing the consumption of all these elements is essential to energy autonomy.

Ultra-low power sensors are shown in the eighth chapter by Pascal Nouet, Norbert Dumas, Laurent Latorre, and Frédérick Mailly from LIRMM. The authors start by introducing some basic notions of a sensor’s proximity electronics, power consumption sources, resolution limits, and performance criteria. Next, a detailed state-of-the-art on capacitive sensor interfaces (for continuous and discrete time) is presented. Finally, resistive sensors and the ways in which their electronic interface’s consumption can be limited are discussed

The ninth chapter, written by Christian Piguet from CSEM, tackles the very low power consumption signal processing in autonomous systems. The author introduces the challenges of digital circuit power and the main low-power techniques. It then details the architectures and performances of low-power digital signal processors. Reducing static consumption, a fundamental challenge for autonomous systems with long sleep times, is analyzed. This chapter concludes with the presentation of some alternative techniques: asynchronous, subthreshold, and error-tolerant logics.

In the tenth chapter, Eric Mercier from CEA Leti considers ultra-low power radio frequency links and protocols, which are often indispensable in autonomous micro- and nanosystems. The author first introduces the constraints due to the frequency plan and the main usable standards for these applications. Home, body, and hybrid networks are shown. In the second section, the author describes existing components and gives a perspective on solutions, still in the research stage, which would allow for flexibility and very small consumption.

I.5. Energy management

Optimizing the flow of energy between producers and consumers of an autonomous microsystem is another major challenge. This optimization can be done on at least two levels: within the microsystem, we can tend toward optimal conversion yields by, say, avoiding any loss of received energy (the energy surplus is systematically stored) or cascade conversions. Such an optimal use of energy implies measuring supply, reserves, and consumption. At the level of a sensor network, we can also optimize the global and local consumption by going toward a multilayer approach, which will consider both hardware and software.

The eleventh chapter, written by Jean-Frédéric Christman, Cyril Condemine, Edith Beigne from CEA Leti, and Christian Piguet from CSEM, tackles energy conversion and its optimal management within the autonomous micro- or nanosystem. The energy consumption characteristics of such systems are discussed, and the architecture choices for the supply system and possible optimizations are presented. Finally, the optimal exploitation of the various operational modes is discussed, and a control with an event-based behavior, based on detecting recovered energy, is described.

To complete this book, energy optimization of sensor networks is presented in the twelfth chapter by Olivier Sentieys and Olivier Berder from the IRISA/INRIA. The authors consider both the hardware parameters, which depend on the structure of the sensor node, and the software parameters, which depend on the algorithms implemented in the node along with the sensor network’s topology and the protocols used. An optimization methodology based on a precise energy model is introduced. Then, conceivable material optimizations and optimization paths for the lowest protocol layers are proposed.

I.6. Bibliography

[ATM 11] WIKIPEDIA, Atmos clock, available at http://en.wikipedia.org/wiki/ Atmos_clock.

[BEL 09] BELLEVILLE M., CANTATORE E., FANET H., FIORINI P., NICOLE P., PELGROM M.J.M., PIGUET C., HAHN R., VANHOOF C., VULLERS R., TARTAGNI M., Energy autonomous systems: future trends in devices, technology, and systems, Report, CATRENE Working Group on Energy Autonomous Systems, 2009

[COX 11] WIKIPEDIA, Cox’s timepiece, available at http://en.wikipedia.org/wiki/Cox%27s_timepiece.

[ECU 11] E-CUBES, 3D integrated micro/nano modules for easily adapted applications, available at http://ecubes.epfl.ch/public/.

[FRA 00] FRANTZ G., “Digital Signal Processor Trends”, IEEE Micro, vol. 20, no. 6, pp. 52–59, November/December 2000.

[PIL 04] PILLOT C., The Worldwide Rechargeable Battery market 2003–2008, available at http://www.rechargebatteries.org/MarketDataRechargeableBatteries.pdf.

[PIS 11] PISTER K., KAHN J., BOSER B., “SMART DUST”, Autonomous Sensing and Communication in a Cubic Millimeter, available at http://robotics.eecs.berkeley.edu/~pister/SmartDust/.

1 Introduction written by Marc BELLEVILLE and Cyril CONDEMINE.

1 This comparison remains difficult to make, as the performances depend on the communication standard used.

2 Data taken from publications on capacitive sensor interfaces.

Chapter 1

Sensors at the Core of Building Control1

1.1. Introduction

To spend less energy, active control of a building seeks to pilot comfort equipment (lighting, heating, air conditioning, etc.) optimally by adapting the operating levels to the real demand as a function of activity, occupation, meteorological conditions, and solar gains. This optimization goes through two conditions:

knowing, with an appropriate spatial resolution, the values of the physical parameters affecting comfort at all times;

predicting the uses and the meteorological and energetic conditions to put the building at an appropriate comfort level in the occupation ranges and to best manage the buildings energy storage capabilities.

Sensors are thus at the core of the process. Having the right information, preparing their large-scale deployment in the building and their easy integration into control systems are essential requirements that were dealt with in HOMES program, a collaborative innovation program.

The chapter presents the key points of our thoughts by focusing on the ambience sensors that supply information to the control functions.

Although they represent a large field of investigation, sensors that are used to measure energy consumption are not discussed in this chapter. They are, however, key to raising awareness of our energy consumption, allowing energy to become visible and thereby evolve toward greater energetic sobriety.

1.2. Sensors in buildings

We currently find two main classes of sensors in buildings, depending on the environment in which they are installed: ambience sensors: these are mainly air temperature, humidity, CO2, presence and luminosity sensors dedicated to HVAC (Heating, Ventilation and Air-Conditioning) and lighting control.

Figure 1.1.Example of ambience sensors

Duct-type sensors: these are air temperature, fluid temperature, CO2, pressure, and air speed sensors to ensure both proper operation of the HVAC system and optimization of flow/fluid distribution.