Triboelectric Devices for Power Generation and Self-Powered Sensing Applications (eBook)

Lokesh Dhakar received his B.E. (Hons.) degree in Mechanical Engineering from Birla Institute of Technology and Science, Pilani in 2010. He received his PhD from NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore in 2016. He also received his MBA from NUS Business School in 2016. His research area of interest includes energy harvesting devices and sensors for healthcare. He is involved in entrepreneurial activities and is passionate about technology commercialization to bring them to markets to actualize their impact in real life.

Supervisor’s Foreword 6
Parts of this thesis have been published in the following journal articles: 8
Acknowledgements 9
Contents 11
Acronyms 14
Symbols 16
List of Figures 18
List of Tables 27
Summary 28
1 Introduction 30
1.1 Motivation 30
1.2 Mechanical Energy Harvesting 32
1.3 Scope and Organization of Thesis 33
References 35
2 Overview of Energy Harvesting Technologies 37
2.1 Mechanical Energy Harvesting Mechanisms 37
2.1.1 Piezoelectric Energy Harvesters 37
2.1.2 Electromagnetic Energy Harvesters 41
2.1.3 Electrostatic Energy Harvesters 43
2.2 Triboelectric Energy Harvesting 45
2.2.1 Out-of-Plane Contact-Separation Mechanism 46
2.2.2 In-Plane Sliding Mechanism 47
2.3 Materials and Fabrication of Triboelectric Nanogenerators 49
2.4 Triboelectric Energy Harvesters and Self-powered Sensors 49
2.4.1 Biomechanical Energy Harvesters 51
2.4.2 Wind Based Energy Harvesters 52
2.4.3 Water Based Energy Harvesters 54
2.4.4 Wearable Energy Harvesters 55
2.4.5 Self-powered Sensors 57
2.4.5.1 Tactile and Pressure Sensors 58
2.4.5.2 Motion Tracking Sensors 59
2.4.5.3 Chemical Sensors 60
2.5 Summary 61
References 62
3 Study of Effect of Topography on Triboelectric Nanogenerator Performance Using Patterned Arrays 66
3.1 Motivation 66
3.2 Cantilever Based TENG—I 67
3.2.1 Device Design 67
3.2.2 Working Mechanism 67
3.2.3 Theory 69
3.2.4 Fabrication Process 73
3.2.5 Broadening of Operating Bandwidth Using Mechanical Stopper 74
3.2.6 Output Voltage and Power 76
3.2.7 Design of Experiment 77
3.2.8 Experimental Setup 78
3.2.9 Results and Discussion 79
3.2.9.1 Effect of Increasing Acceleration 79
3.2.9.2 Calculation of Charge Density 80
3.2.9.3 Voltage and Power Characteristics 81
3.2.9.4 Broadband Characteristics of Cantilever TENG—I 81
3.2.9.5 Effect of Fill Factor on Power Generation 82
3.3 Cantilever Based TENG—II 84
3.3.1 Device Design and Fabrication 84
3.3.2 Deformation in the PDMS Micropad Patterns 85
3.3.3 Results and Discussion 88
3.3.3.1 Broadband Behavior of Cantilever TENG—II 88
3.3.3.2 Output Characteristics of Cantilever TENG—II 89
3.3.3.3 Effect of PDMS Micropad Array Configuration on Device Performance 89
3.4 Summary 92
References 92
4 Skin Based Self-powered Wearable Sensors and Nanogenerators 94
4.1 Motivation 94
4.2 Skin Used as a Triboelectric Material 94
4.2.1 Device Design 95
4.2.2 Device Fabrication 95
4.2.3 Working Mechanism 97
4.2.4 Harvesting Energy Using Skin Based Triboelectric Nanogenerator from Various Human Activities 98
4.2.5 Testing as a Motion Sensor 101
4.3 Integration of Skin Based Nanogenerator with a Capacitance Based Sensor to Realize Human Finger Motion Tracking 102
4.3.1 Fabrication 103
4.3.2 Operating Principle of Sensor 103
4.3.3 Working of Triboelectric Nanogenerator 106
4.3.4 Finger Motion Sensor Testing 107
4.3.5 Energy Harvesting Testing 111
4.4 Summary 112
References 112
5 Large Scale Fabrication of Triboelectric Energy Harvesting and Sensing Applications 113
5.1 Motivation 113
5.2 Large Scale Energy Harvesting Using Roll-to-Roll Fabrication Process 114
5.2.1 Fabrication Process 114
5.2.1.1 Fabrication of Mold 114
5.2.1.2 Roll-to-Roll UV Embossing of Patterned PET Films 115
5.2.1.3 Assembly of LS-TENG 116
5.2.2 Working Mechanism 119
5.2.3 Effect of Different Embossed Patterns 120
5.2.4 Applications in Energy Harvesting 121
5.3 Triboelectric Pressure Sensor Arrays Using Roll-to-Roll UV Embossed Films 123
5.3.1 Fabrication and Assembly 123
5.3.2 Sensor Array Characterization 125
5.3.3 Motion Tracking and Security Applications 127
5.3.4 Applications in Posture Tracking 130
5.4 Summary 131
References 131
6 Triboelectric Mechanism for Bidirectional Tactile Sensing and Energy Harvesting 133
6.1 Motivation 133
6.2 Design and Fabrication 133
6.2.1 Device Configuration 133
6.2.2 Working Principle 134
6.2.3 Fabrication 136
6.2.3.1 Bottom Part Fabrication 136
6.2.3.2 Top Part Fabrication 137
6.2.3.3 Assembly 138
6.3 Experiments and Discussion 139
6.3.1 Tactile Sensing 139
6.3.2 Energy Harvesting Applications 141
6.4 Summary 143
References 144
7 Conclusion and Recommendations for Future Work 145
7.1 Conclusions 145
7.2 Future Work 146
7.2.1 High Current Output Triboelectric Nanogenerator 146
7.2.2 Power Management Electronics 146
7.2.3 Contributions 146
References 147
Appendix: Modeling Equations for Finger Movement Using Joint Angle and Length Between Joint 148