Electrostatic Kinetic Energy Harvesting [Hardcover]

Harvesting kinetic energy is a good opportunity to power wireless sensor in a vibratory environment. Besides classical methods based on electromagnetic and piezoelectric mechanisms, electrostatic transduction has a great perspective in particular when dealing with small devices based on MEMS technology. This book describes in detail the principle of such capacitive Kinetic Energy Harvesters based on a spring-mass system. Specific points related to the design and operation of kinetic energy harvesters (KEHs) with a capacitive interface are presented in detail: advanced studies on their nonlinear features, typical conditioning circuits and practical MEMS fabrication.

Preface ix

Introduction: Background and Area of Application xi

Chapter 1. Introduction to Electrostatic Kinetic Energy Harvesting 1

Chapter 2. Capacitive Transducers 7

2.1. Presentation of capacitive transducers 7

2.2. Electrical operation of a variable capacitor 11

2.3. Energy and force in capacitive transducers 12

2.3.1. Energy of a capacitor 12

2.3.2. Force of the capacitor 14

2.3.3. Capacitive transducers biased by an electret layer 17

2.4. Energy conversion with a capacitive transducer 20

2.5. Optimization of the operation of a capacitive transducer 21

2.6. Electromechanical coupling 23

2.7. Conclusions 24

2.8. Appendix: proof of formula [2.32] for the energy converted in a cycle 24

Chapter 3. Mechanical Aspects of Kinetic Energy Harvesters: Linear Resonators 27

3.1. Overview of mechanical forces and the resonator model 27

3.1.1. Linear resonator as the main model of the mechanical part 27