With its inclusion of the fundamentals, systems and applications, this reference provides readers with the basics of micro energy conversion along with expert knowledge on system electronics and real-life microdevices.
The authors address different aspects of energy harvesting at the micro scale with a focus on miniaturized and microfabricated devices. Along the way they provide an overview of the field by compiling knowledge on the design, materials development, device realization and aspects of system integration, covering emerging technologies, as well as applications in power management, energy storage, medicine and low-power system electronics. In addition, they survey the energy harvesting principles based on chemical, thermal, mechanical, as well as hybrid and nanotechnology approaches.
In unparalleled detail this volume presents the complete picture — and a peek into the future — of micro-powered microsystems.
Tabella dei contenuti
About the Volume Editors XVII
List of Contributors XIX
1 Introduction to Micro Energy Harvesting 1
Danick Briand, Eric Yeatman, and Shad Roundy
1.1 Introduction to the Topic 1
1.2 Current Status and Trends 3
1.3 Book Content and Structure 4
2 Fundamentals of Mechanics and Dynamics 7
Helios Vocca and Luca Gammaitoni
2.1 Introduction 7
2.2 Strategies for Micro Vibration Energy Harvesting 8
2.2.1 Piezoelectric 9
2.2.2 Electromagnetic 10
2.2.3 Electrostatic 11
2.2.4 From Macro to Micro to Nano 11
2.3 Dynamical Models for Vibration Energy Harvesters 12
2.3.1 Stochastic Character of Ambient Vibrations 14
2.3.2 Linear Case 1: Piezoelectric Cantilever Generator 14
2.3.3 Linear Case 2: Electromagnetic Generator 15
2.3.4 Transfer Function 15
2.4 Beyond Linear Micro-Vibration Harvesting 16
2.4.1 Frequency Tuning 16
2.4.2 Multimodal Harvesting 17
2.4.3 Up-Conversion Techniques 17
2.5 Nonlinear Micro-Vibration Energy Harvesting 18
2.5.1 Bistable Oscillators: Cantilever 19
2.5.2 Bistable Oscillators: Buckled Beam 21
2.5.3 Monostable Oscillators 23
2.6 Conclusions 24
Acknowledgments 24
References 24
3 Electromechanical Transducers 27
Adrien Badel, Fabien Formosa, and Mickaël Lallart
3.1 Introduction 27
3.2 Electromagnetic Transducers 27
3.2.1 Basic Principle 27
3.2.1.1 Induced Voltage 28
3.2.1.2 Self-Induction 28
3.2.1.3 Mechanical Aspect 29
3.2.2 Typical Architectures 30
3.2.2.1 Case Study 30
3.2.2.2 General Case 33
3.2.3 Energy Extraction Cycle 33
3.2.3.1 Resistive Cycle 34
3.2.3.2 Self-Inductance Cancelation 34
3.2.3.3 Cycle with Rectification 35
3.2.3.4 Active Cycle 36
3.2.4 Figures of Merit and Limitations 36
3.3 Piezoelectric Transducers 37
3.3.1 Basic Principles and Constitutive Equations 37
3.3.1.1 Physical Origin of Piezoelectricity in Ceramics and Crystals 37
3.3.1.2 Constitutive Equations 38
3.3.2 Typical Architectures for Energy Harvesting 39
3.3.2.1 Modeling 39
3.3.2.2 Application to Typical Configurations 40
3.3.3 Energy Extraction Cycles 41
3.3.3.1 Resistive Cycles 41
3.3.3.2 Cycles with Rectification 43
3.3.3.3 Active Cycles 43
3.3.3.4 Comparison 43
3.3.4 Maximal Power Density and Figure of Merit 44
3.4 Electrostatic Transducers 45
3.4.1 Basic Principles 45
3.4.1.1 Gauss’s Law 45
3.4.1.2 Capacitance C0 45
3.4.1.3 Electric Potential 46
3.4.1.4 Energy 46
3.4.1.5 Force 47
3.4.2 Design Parameters for a Capacitor 47
3.4.2.1 Architecture 47
3.4.2.2 Dielectric 48
3.4.3 Energy Extraction Cycles 48
3.4.3.1 Charge-Constrained Cycle 49
3.4.3.2 Voltage-Constrained Cycle 50
3.4.3.3 Electret Cycle 51
3.4.4 Limits 51
3.4.4.1 Parasitic Capacitors 51
3.4.4.2 Breakdown Voltage 53
3.4.4.3 Pull-In Force 53
3.5 Other Electromechanical Transduction Principles 53
3.5.1 Electrostrictive Materials 53
3.5.1.1 Physical Origin and Constitutive Equations 53
3.5.1.2 Energy Harvesting Strategies 54
3.5.2 Magnetostrictive Materials 55
3.5.2.1 Physical Origin 55
3.5.2.2 Constitutive Equations 56
3.6 Effect of the Vibration Energy Harvester Mechanical Structure 56
3.7 Summary 58
References 59
4 Thermal Fundamentals 61
Mathieu Francoeur
4.1 Introduction 61
4.2 Fundamentals of Thermoelectric Power Generation 62
4.2.1 Overview of Nanoscale Heat Conduction and the Seebeck Effect 62
4.2.2 Heat Transfer Analysis of Thermoelectric Power Generation 64
4.3 Near-Field Thermal Radiation and Thermophotovoltaic Power Generation 66
4.3.1 Introduction 66
4.3.2 Theoretical Framework: Fluctuational Electrodynamics 67
4.3.3 Introduction to Thermophotovoltaic Power Generation and Physics of Near-Field Radiative Heat Transfer between Two Bulk Materials Separated by a Subwavelength Vacuum Gap 70
4.3.4 Nanoscale-Gap Thermophotovoltaic Power Generation 76
4.4 Conclusions 80
Acknowledgments 80
References 81
5 Power Conditioning for Energy Harvesting – Theory and Architecture 85
Stephen G. Burrow and Paul D.Mitcheson
5.1 Introduction 85
5.2 The Function of Power Conditioning 85
5.2.1 Interface to the Harvester 86
5.2.2 Circuits with Resistive Input Impedance 87
5.2.3 Circuits with Reactive Input Impedance 89
5.2.4 Circuits with Nonlinear Input Impedance 90
5.2.5 Peak Rectifiers 90
5.2.6 Piezoelectric Pre-biasing 92
5.2.7 Control 94
5.2.7.1 Voltage Regulation 94
5.2.7.2 Peak Power Controllers 96
5.2.8 System Architectures 97
5.2.8.1 Start-Up 97
5.2.9 Highly Dynamic Load Power 98
5.3 Summary 100
References 100
6 Thermoelectric Materials for Energy Harvesting 103
Andrew C.Miner
6.1 Introduction 103
6.2 Performance Considerations in Materials Selection: z T 103
6.2.1 Properties of Chalcogenides (Group 16) 106
6.2.2 Properties of Crystallogens (Group 14) 106
6.2.3 Properties of Pnictides (Group 15) 107
6.2.4 Properties of Skutterudites 108
6.3 Influence of Scale on Material Selection and Synthesis 110
6.3.1 Thermal Conductance Mismatch 111
6.3.2 Domination of Electrical Contact Resistances 112
6.3.3 Domination of Bypass Heat Flow 113
6.3.4 Challenges in Thermoelectric Property Measurement 113
6.4 Low Dimensionality: Internal Micro/Nanostructure and Related Approaches 114
6.5 Thermal Expansion and Its Role in Materials Selection 115
6.6 Raw Material Cost Considerations 116
6.7 Material Synthesis with Particular Relevance to Micro Energy Harvesting 116
6.7.1 Electroplating, Electrophoresis, Dielectrophoresis 117
6.7.2 Thin and Thick Film Deposition 118
6.8 Summary 118
References 119
7 Piezoelectric Materials for Energy Harvesting 123
Emmanuel Defay, Sébastien Boisseau, and Ghislain Despesse
7.1 Introduction 123
7.2 What Is Piezoelectricity? 123
7.3 Thermodynamics: the Right Way to Describe Piezoelectricity 125
7.4 Material Figure of Merit: the Electromechanical Coupling Factor 126
7.4.1 Special Considerations for Energy Harvesting 128
7.5 Perovskite Materials 129
7.5.1 Structure 129
7.5.1.1 Ferroelectricity in Perovskites 129
7.5.1.2 Piezoelectricity in Perovskites: Poling Required 131
7.5.2 PZT Phase Diagram 131
7.5.3 Ceramics 132
7.5.3.1 Fabrication Process 132
7.5.3.2 Typical Examples for Energy Harvesting 134
7.5.4 Bulk Single Crystals 135
7.5.4.1 Perovskites 135
7.5.4.2 Energy Harvesting with Perovskites Bulk Single Crystals 135
7.5.5 Polycrystalline Perovskites Thin Films 136
7.5.5.1 Fabrication Processes 136
7.5.5.2 Energy Harvesting with Poly-PZT Films 136
7.5.6 Single-Crystal Thin Films 137
7.5.6.1 Fabrication Process 137
7.5.6.2 Energy Harvesting with SC Perovskite Films 137
7.5.7 Lead-Free 138
7.5.7.1 Energy Harvesting with Lead-Free Materials 139
7.6 Wurtzites 139
7.6.1 Structure 139
7.6.2 Thin Films and Energy Harvesting 140
7.6.3 Doping 141
7.7 PVDFs 141
7.7.1 Structure 141
7.7.2 Synthesis 143
7.7.3 Energy Harvesters with PVDF 143
7.8 Nanomaterials 143
7.9 Typical Values for the Main Piezoelectric Materials 144
7.10 Summary 145
References 145
8 Electrostatic/Electret-Based Harvesters 149
Yuji Suzuki
8.1 Introduction 149
8.2 Electrostatic/Electret Conversion Cycle 149
8.3 Electrostatic/Electret Generator Models 151
8.3.1 Configuration of Electrostatic/Electret Generator 151
8.3.2 Electrode Design for Electrostatic/Electret Generator 153
8.4 Electrostatic Generators 156
8.4.1 Design and Fabrication Methods 156
8.4.2 Generator Examples 158
8.5 Electrets and Electret Generator Model 160
8.5.1 Electrets 160
8.5.2 Electret Materials 161
8.5.3 Charging Technologies 162
8.5.4 Electret Generator Model 163
8.6 Electret Generators 168
8.7 Summary 171
References 171
9 Electrodynamic Vibrational Energy Harvesting 175
Shuo Cheng, Clemens Cepnik, and David P. Arnold
9.1 Introduction 175
9.2 Theoretical Background 178
9.2.1 Energy Storage, Dissipation, and Conversion 178
9.2.2 Electrodynamic Physics 179
9.2.2.1 Faraday’s Law 179
9.2.2.2 Lorentz Force 180
9.2.3 Simplified Electrodynamic Equations 180
9.3 Electrodynamic Harvester Architectures 181
9.4 Modeling and Optimization 183
9.4.1 Modeling 184
9.4.1.1 Lumped Element Method 184
9.4.1.2 Finite Element Method 188
9.4.1.3 Combination of Lumped Element Model and Finite Element Model 189
9.4.2 Optimization 190
9.5 Design and Fabrication 191
9.5.1 Design of Electrodynamic Harvesters 192
9.5.2 Fabrication of Electrodynamic Harvesters 194
9.6 Summary 196
References 197
10 Piezoelectric MEMS Energy Harvesters 201
Jae Yeong Park
10.1 Introduction 201
10.1.1 The General Governing Equation 202
10.1.2 Design Consideration 203
10.2 Development of Piezoelectric MEMS Energy Harvesters 204
10.2.1 Overview 204
10.2.2 Fabrication Technologies 205
10.2.3 Characterization 211
10.2.3.1 Frequency Response 211
10.2.3.2 Output Power of Piezoelectric MEMS Energy Harvesters 211
10.3 Challenging Issues in Piezoelectric MEMS Energy Harvesters 213
10.3.1 Output Power 213
10.3.2 Frequency Response 215
10.3.3 Piezoelectric Material 217
10.4 Summary 218
References 218
11 Vibration Energy Harvesting from Wideband and Time-Varying Frequencies 223
Lindsay M.Miller
11.1 Introduction 223
Contents XI
11.1.1 Motivation 223
11.1.2 Classification of Devices 223
11.1.3 General Comments 225
11.2 Active Schemes for Tunable Resonant Devices 225
11.2.1 Stiffness Modification for Frequency Tuning 226
11.2.1.1 Modify L 226
11.2.1.2 Modify E 227
11.2.1.3 Modify keff Using Axial Force 227
11.2.1.4 Modify keff Using an External Spring 229
11.2.1.5 Modify keff Using an Electrical External Spring 231
11.2.2 Mass Modification for Frequency Tuning 232
11.3 Passive Schemes for Tunable Resonant Devices 232
11.3.1 Modify meff by Coupling Mass Position with Beam Excitation 233
11.3.2 Modify keff by Coupling Axial Force with Centrifugal Force from Rotation 234
11.3.3 Modify L by Using Centrifugal Force to Toggle Beam Clamp Position 234
11.4 Wideband Devices 235
11.4.1 Multimodal Designs 236
11.4.2 Nonlinear Designs 237
11.5 Summary and Future Research Directions 240
11.5.1 Summary of Tunable and Wideband Strategies 240
11.5.2 Areas for Future Improvement in Tunable and Wideband Strategies 241
11.5.2.1 Tuning range and resolution 241
11.5.2.2 Tuning sensitivity to driving vibrations 242
11.5.2.3 System Size considerations 242
References 243
12 Micro Thermoelectric Generators 245
Ingo Stark
12.1 Introduction 245
12.2 Classification of Micro Thermoelectric Generators 247
12.3 General Considerations for Micro TEGs 250
12.4 Micro Device Technologies 252
12.4.1 Research and Development 253
12.4.1.1 Electrodeposition 253
12.4.1.2 Silicon-MEMS Technology 253
12.4.1.3 CMOS-MEMS Technology 254
12.4.1.4 Other 255
12.4.2 Commercialized Micro Technologies 257
12.4.2.1 Micropelt Technology 257
12.4.2.2 Nextreme/Laird Technology 258
12.4.2.3 Thermogen Technology 259
12.5 Applications of Complete Systems 260
12.5.1 Energy-Autonomous Sensor for Air Flow Temperature 261
12.5.2 Wireless Pulse Oximeter Sp O2 Sensor 261
12.5.3 Intelligent Thermostatic Radiator Valve (i TRV) 262
12.5.4 Wireless Power Generator Evaluation Kit 263
12.5.5 Jacket-Integrated Wireless Temperature Sensor 263
12.6 Summary 264
References 265
13 Micromachined Acoustic Energy Harvesters 271
Stephen Horowitz and Mark Sheplak
13.1 Introduction 271
13.2 Historical Overview 272
13.2.1 A Brief History 272
13.2.2 Survey of Reported Performance 274
13.3 Acoustics Background 276
13.3.1 Principles and Concepts 276
13.3.2 Fundamentals of Acoustics 276
13.3.3 Challenges of Acoustic Energy Harvesting 277
13.4 Electroacoustic Transduction 277
13.4.1 Modeling 278
13.4.1.1 Lumped Element Modeling (LEM) 278
13.4.1.2 Equivalent Circuits 279
13.4.1.3 Transduction 280
13.4.1.4 Numerical Approaches 281
13.4.2 Impedance Matching and Energy Focusing 281
13.4.3 Transduction Methods 281
13.4.3.1 Piezoelectric Transduction 281
13.4.3.2 Electromagnetic Transduction 282
13.4.3.3 Electrostatic Transduction 282
13.4.3.4 Comparative Analysis 283
13.4.4 Transduction Structures 284
13.4.4.1 Structures for Impedance Matching 284
13.4.4.2 Structures for Acoustical to Mechanical Transduction 286
13.5 Fabrication Methods 288
13.5.1 Materials 288
13.5.2 Processes 289
13.6 Testing and Characterization 289
13.7 Summary 290
Acknowledgments 290
References 290
14 Energy Harvesting from Fluid Flows 297
Andrew S. Holmes
14.1 Introduction 297
14.2 Fundamental and Practical Limits 298
Contents XIII
14.3 Miniature Wind Turbines 301
14.3.1 Scaling Effects in Miniature Wind Turbines 302
14.3.1.1 Turbine Performance 302
14.3.1.2 Generator and Bearing Losses 305
14.4 Energy Harvesters Based on Flow Instability 306
14.4.1 Vortex Shedding Devices 307
14.4.2 Devices Based on Galloping and Flutter 310
14.5 Performance Comparison 316
14.6 Summary 317
References 317
15 Far-Field RF Energy Transfer and Harvesting 321
Hubregt J. Visser and Ruud Vullers
15.1 Introduction 321
15.2 Nonradiative and Radiative (Far-Field) RF Energy Transfer 322
15.2.1 Nonradiative Transfer 322
15.2.2 Radiative Transfer 323
15.2.3 Harvesting versus Transfer 324
15.3 Receiving Rectifying Antenna 326
15.3.1 Antenna–Rectifier Matching 326
15.3.1.1 Voltage Boosting Technique 327
15.3.1.2 Antenna Matched to Rectifier 328
15.3.1.3 Antenna Not Matched to the Rectifier/Multiplier 329
15.3.1.4 Consequences for the Rectifier and the Antenna Design 330
15.4 Rectifier 330
15.4.1 RF Input Impedance 331
15.4.2 DC Output Voltage 332
15.4.3 Antenna 334
15.4.3.1 50 Ω Antenna 335
15.4.3.2 Complex Conjugately Matched Antenna 335
15.4.4 Rectenna Results 336
15.4.5 Voltage Up-Conversion 339
15.5 Transmission 340
15.6 Examples and Future Perspectives 341
15.7 Conclusions 344
References 344
16 Microfabricated Microbial Fuel Cells 347
Hao Ren and Junseok Chae
16.1 Introduction 347
16.2 Fundamentals of MEMS MFC 348
16.2.1 Operation Principle 348
16.2.1.1 Structure 348
16.2.1.2 Materials 350
16.2.2 Critical Parameters for Testing 350
16.2.2.1 Anode and Cathode Potential, the Total Cell Potential 350
16.2.2.2 Open Circuit Voltage (EOCV) 351
16.2.2.3 Areal/Volumetric Current Density and Areal/Volumetric Power Density 351
16.2.2.4 Internal Resistance and Areal Resistivity 352
16.2.2.5 Efficiency 353
16.3 Prior Art MEMS MFCS 354
16.4 Future Work 355
16.4.1 Reducing Areal Resistivity 355
16.4.1.1 Applying Materials with High Surface-Area-to-Volume Ratio 355
16.4.1.2 Mitigating Oxygen Intrusion 358
16.4.2 Autonomous Running 359
16.4.3 Elucidating the EET Mechanism 359
References 359
17 Micro Photovoltaic Module Energy Harvesting 363
Shunpu Li , Wensi Wang, Ningning Wang, Cian O’Mathuna, and Saibal Roy
17.1 Introduction 363
17.1.1 p-n Junction and Crystalline Si Solar Cells 363
17.1.2 Amorphous Silicon Solar Cell 366
17.1.3 CIGS and Cd Te Solar Cell Development 367
17.1.4 Polymer Solar Cell 370
17.1.5 Dye-Sensitized Solar Cells (DSSC) 373
17.2 Monolithically Integration of Solar Cells with IC 375
17.3 Low-Power Micro Photovoltaic Systems 376
17.3.1 Maximum Power Point Tracking 376
17.3.2 Output Voltage Regulation 379
17.3.3 Indoor-Light-Powered Wireless Sensor Networks – a Case Study 380
17.4 Summary 382
References 383
18 Power Conditioning for Energy Harvesting – Case Studies and Commercial Products 385
Paul D.Mitcheson and Stephen G. Burrow
18.1 Introduction 385
18.2 Submilliwatt Electromagnetic Harvester Circuit Example 386
18.3 Single-Supply Pre-biasing for Piezoelectric Harvesters 388
18.4 Ultra-Low-Power Rectifier and MPPT for Thermoelectric Harvesters 392
18.5 Frequency Tuning of an Electromagnetic Harvester 393
18.6 Examples of Converters for Ultra-Low-Output Transducers 396
18.7 Power Processing for Electrostatic Devices 397
18.8 Commercial Products 397
18.9 Conclusions 398
References 399
19 Micro Energy Storage: Considerations 401
Dan Steingart
19.1 Introduction 401
19.2 Boundary Conditions 401
19.2.1 Microbatteries 404
19.2.2 Supercapacitors 405
19.3 Primary Energy Storage Approaches 405
19.3.1 Volume-Constrained versus Conformally Demanding Approaches 408
19.3.2 Caveat Emptor 409
19.3.3 Future Work and First-Order Problems 409
References 410
20 Thermoelectric Energy Harvesting in Aircraft 415
Thomas Becker, Alexandros Elefsiniotis, and Michail E. Kiziroglou
20.1 Introduction 415
20.2 Aircraft Standardization 416
20.3 Autonomous Wireless Sensor Systems 417
20.4 Thermoelectric Energy Harvesting in Aircraft 419
20.4.1 Efficiency of a Thermoelectric Energy Harvesting Device 420
20.4.2 Static Thermoelectric Energy Harvester 421
20.4.3 Dynamic Thermoelectric Energy Harvester 423
20.5 Design Considerations 425
20.6 Applications 427
20.6.1 Static Thermoelectric Harvester for Aircraft Seat Sensors 427
20.6.2 The Dynamic Thermoelectric Harvesting Prototype 428
20.6.3 Heat Storage Thermoelectric Harvester for Aircraft Strain Sensors 428
20.6.4 Outlook 430
20.7 Conclusions 432
References 433
21 Powering Pacemakers with Heartbeat Vibrations 435
M. Amin Karami and Daniel J. Inman
21.1 Introduction 435
21.2 Design Specifications 436
21.3 Estimation of Heartbeat Oscillations 437
21.4 Linear Energy Harvesters 438
21.5 Monostable Nonlinear Harvesters 441
21.6 Bistable Harvesters 446
21.7 Experimental Investigations 450
21.8 Heart Motion Characterization 450
21.9 Conclusions 456
Acknowledgment 457
References 457
Index 459
Circa l’autore
Danick Briand obtained his Ph D degree in the field of micro-chemical systems from the Institute of Microtechnology (IMT), University of Neuchatel, Switzerland, in 2001. He is currently a team leader at EPFL IMT Samlab in the field of Enviro MEMS, Energy and Enviromental MEMS. He has been awarded the Eurosensors Fellowship in 2010. He has been author or co-author on more than 150 papers published in scientific journals and conference proceedings. He is a member of several scientific and technical conference committees in the field of sensors and MEMS, participating also in the organization of workshop and conferences. His research interests in the field of sensors and microsystems include environmental and energy MEMS.
Eric M. Yeatman has been a member of academic staff in Imperial College London since 1989, and Professor of Micro-Engineering since 2005. He is Deputy Head of the Department of Electrical and Electronic Engineering, and has published more than 160 papers and patents on optical devices and materials, and micro-electro-mechanical systems. In 2011 he was awarded the Royal Academy of Engineering Silver Medal. He has been principal or co-investigator on more than 20 research projects, and has acted as a design consultant for several international companies. His current research interests are in radio frequency and photonic MEMS devices, energy sources for wireless devices, and sensor networks.