Description

About the Authors xiPreface xiiiAcknowledgments xv1 Introduction 11.1 Background 11.2 Energy Harvesters 21.2.1 Piezoelectric ZnO Energy Harvester 31.2.2 Vibrational Electromagnetic Generators 31.2.3 Rotary Electromagnetic Generators 41.2.4 NFES Piezoelectric PVDF Energy Harvester 41.3 Overview 52 Design and Fabrication of Flexible Piezoelectric Generators Based on ZnO Thin Films 72.1 Introduction 72.2 Characterization and Theoretical Analysis of Flexible ZnO-Based Piezoelectric Harvesters 102.2.1 Vibration Energy Conversion Model of Film-Based Flexible Piezoelectric Energy Harvester 102.2.2 Piezoelectricity and Polarity Test of Piezoelectric ZnO Thin Film 122.2.3 Optimal Thickness of PET Substrate 152.2.4 Model Solution of Cantilever Plate Equation 152.2.5 Vibration-Induced Electric Potential and Electric Power 182.2.6 Static Analysis to Calculate the Optimal Thickness of the PET Substrate 192.2.7 Model Analysis and Harmonic Analysis 212.2.8 Results of Model Analysis and Harmonic Analysis 232.3 The Fabrication of Flexible Piezoelectric ZnO Harvesters on PET Substrates 272.3.1 Bonding Process to Fabricate UV-Curable Resin Lump Structures on PET Substrates 272.3.2 Near-Field Electro-Spinning with Stereolithography Technique to Directly Write 3D UV-Curable Resin Patterns on PET Substrates 292.3.3 Sputtering of Al and ITO Conductive Thin Films on PET Substrates 292.3.4 Deposition of Piezoelectric ZnO Thin Films by Using RF Magnetron Sputtering 312.3.5 Testing a Single Energy Harvester under Resonant and Non-Resonant Conditions 342.3.6 Application of ZnO/PET-Based Generator to Flash Signal LED Module 392.3.7 Design and Performance of a Broad Bandwidth Energy Harvesting System 402.4 Fabrication and Performance of Flexible ZnO/SUS304-Based Piezoelectric Generators 482.4.1 Deposition of Piezoelectric ZnO Thin Films on Stainless Steel Substrates 482.4.2 Single-Sided ZnO/SUS304-Based Flexible Piezoelectric Generator 502.4.3 Double-Sided ZnO/SUS304-Based Flexible Piezoelectric Generator 512.4.4 Characterization of ZnO/SUS304-Based Flexible Piezoelectric Generators 522.4.5 Structural and Morphological Properties of Piezoelectric ZnO Thin Films on Stainless Steel Substrates 542.4.6 Analysis of Adhesion of ZnO Thin Films on Stainless Steel Substrates 562.4.7 Electrical Properties of Single-Sided ZnO/SUS304-Based Flexible Piezoelectric Generator 592.4.8 Characterization of Double-Sided ZnO/SUS304-Based Flexible Piezoelectric Generator: Analysis and Modification of Back Surface of SUS304 612.4.9 Electrical Properties of Double-Sided ZnO/SUS304-Based Piezoelectric Generator 632.5 Summary 66References 673 Design and Fabrication of Vibration-Induced Electromagnetic Microgenerators 713.1 Introduction 713.2 Comparisons between MCTG and SMTG 743.2.1 Magnetic Core-Type Generator (MCTG) 743.2.2 Sided Magnet-Type Generator (SMTG) 763.3 Analysis of Electromagnetic Vibration-Induced Microgenerators 763.3.1 Design of Electromagnetic Vibration-Induced Microgenerators 773.3.2 Analysis Mode of the Microvibration Structure 783.3.3 Analysis Mode of Magnetic Field 813.3.4 Evaluation of Various Parameters of Power Output 843.4 Analytical Results and Discussion 883.4.1 Analysis of Bending Stress within the Supporting Beam of the Spiral Microspring 903.4.2 Finite Element Models for Magnetic Density Distribution 933.4.3 Power Output Evaluation 973.5 Fabrication of Microcoil for Microgenerator 1033.5.1 Microspring and Induction Coil 1033.5.2 Microspring and Magnet 1053.6 Tests and Experiments 1063.6.1 Measurement System 1063.6.2 Measurement Results and Discussion 1073.6.3 Comparison between Measured Results and Analytical Values 1103.7 Conclusions 1123.7.1 Analysis of Microgenerators and Vibration Mode and Simulation of the Magnetic Field 1123.7.2 Fabrication of LTCC Microsensor 1123.7.3 Measurement and Analysis Results 1133.8 Summary 113References 1144 Design and Fabrication of Rotary Electromagnetic Microgenerator 1174.1 Introduction 1174.1.1 Piezoelectric, Thermoelectric, and Electrostatic Generators 1194.1.2 Vibrational Electromagnetic Generators 1194.1.3 Rotary Electromagnetic Generators 1204.1.4 Generator Processes 1214.1.5 Lithographie Galvanoformung Abformung Process 1224.1.6 Winding Processes 1234.1.7 LTCC 1234.1.8 Printed Circuit Board Processes 1244.1.9 Finite-Element Simulation and Analytical Solutions 1264.2 Case 1: Winding Generator 1264.2.1 Design 1274.2.2 Analytical Formulation 1324.2.3 Simulation 1344.2.4 Fabrication Process 1384.2.5 Results and Discussion (1) 1394.2.6 Results and Discussion (2) 1424.3 Case 2: LTCC Generator 1464.3.1 Simulation 1474.3.2 Analytical Theorem of Microgenerator Electromagnetism 1484.3.3 Simplification 1524.3.4 Analysis of Vector Magnetic Potential 1534.3.5 Analytical Solutions for Power Generation 1544.4 Fabrication 1574.4.1 LTCC Process 1574.4.2 Magnet Process 1594.4.3 Measurement Set-up 1604.5 Results and Discussion 1624.5.1 Design 1624.5.2 Analytical Solutions 1684.5.3 Fabrication 170References 1785 Design and Fabrication of Electrospun PVDF Piezo-Energy Harvesters 1835.1 Introduction 1835.2 Fundamentals of Electrospinning Technology 1875.2.1 Introduction to Electrospinning 1875.2.2 Alignment and Assembly of Nanofibers 1905.3 Near-Field Electrospinning 1915.3.1 Introduction and Background 1915.3.2 Principles of Operation 1945.3.3 Process and Experiment 1965.3.4 Summary 2025.4 Continuous NFES 2025.4.1 Introduction and Background 2025.4.2 Principles of Operation 2025.4.3 Controllability and Continuity 2055.4.4 Process Characterization 2085.4.5 Summary 2115.5 Direct-Write Piezoelectric Nanogenerator 2115.5.1 Introduction and Background 2115.5.2 Polyvinylidene Fluoride 2125.5.3 Theoretical Studies for Realization of Electrospun PVDF Nanofibers 2135.5.4 Electrospinning of PVDF Nanofibers 2165.5.5 Detailed Discussion of Process Parameters 2195.5.6 Experimental Realization of PVDF Nanogenerator 2235.5.7 Summary 2415.6 Materials, Structure, and Operation of Nanogenerator with Future Prospects 2415.6.1 Material and Structural Characteristics 2415.6.2 Operation of Nanogenerator 2435.6.3 Summary and Future Prospects 2485.7 Case Study: Large-Array Electrospun PVDF Nanogenerators on a Flexible Substrate 2485.7.1 Introduction and Background 2485.7.2 Working Principle 2495.7.3 Device Fabrication 2495.7.4 Experimental Results 2515.7.5 Summary 2525.8 Conclusion 2535.8.1 Near-Field Electrospinning 2535.8.2 Continuous Near-Field Electrospinning 2545.8.3 Direct-Write Piezoelectric PVDF 2545.9 Future Directions 2555.9.1 NFES Integrated Nanofiber Sensors 2555.9.2 NFES One-Dimensional Sub-Wavelength Waveguide 2565.9.3 NFES Biological Applications 2575.9.4 Direct-Write Piezoelectric PVDF Nanogenerators 258References 258Index 265