Title Page
Contents
Abstract 18
Chapter 1. INTRODUCTION 20
1.1. Energy harvesting 20
1.1.1. Triboelectric energy harvesting 24
1.1.2. Electromagnetic wave energy harvesting 31
1.2. Surface charge control of materials 33
Chapter 2. Metal nanowire-polymer composite layer for surface charge control 36
2.1. Abstract 36
2.2. Introduction 37
2.3. Experimental details 39
2.3.1. Fabrication of experimental samples 39
2.3.2. Characterization 44
2.4. Results and discussion 45
2.4.1. Surface potential of composite film 45
2.4.2. Principle of change in surface potential of composite film 49
2.4.3. Output evaluation of TENG based on composite film 51
2.4.4. FEM simulation for verifying the principle of charge transfer 54
2.5 Conclusion 57
Chapter 3. Self-powered fine dust filtration system using tribo-electrification induced electric field 58
3.1. Abstract 58
3.2. Introduction 59
3.3. Experimental details 62
3.3.1. Fabrication of TENG and charging, collector part 62
3.3.2. PM generation and efficiency measurement 63
3.3.3. Characterization 64
3.4. Results and discussions 64
3.4.1. Working principle of TENG 64
3.4.2. Performance characterization of rotation TENG 72
3.4.3. Working principle of TE filtration system 74
3.4.4. Crucial parameter investigation using FEM simulation 78
3.4.5. Filtration performance of TE dust filtration system 81
3.5. Conclusion 85
Chapter 4. Electrical bandage based on body-coupled energy harvesting for effective electrical stimulation to accelerate wound healing 86
4.1. Abstract 86
4.2. Introduction 87
4.3. Experimental details 92
4.3.1. Materials and electrical bandage preparation 92
4.3.2. Materials characterization 94
4.3.3. Electrical characterizations 95
4.3.4. In vivo experiments 95
4.3.5. In vitro scratch assay and proliferation assay 96
4.3.6. Western blot analysis 97
4.3.7. Statistical analyses 98
4.4. Results and discussion 98
4.4.1. Design and mechanisms of the electrical bandage 98
4.4.2. High-permittivity P(VDF-TrFE):CCTO nano-composite for effective electrical stimulation 104
4.4.3. Application on an in vitro human model for wound healing acceleration 109
4.4.4. In vivo demonstrations of the acceleration of wound healing by electrical stimulation 114
4.5. Conclusion 117
References 120
Reference 1 120
Reference 2 122
Reference 3 123
Reference 4 126
논문요약 130
List of Publications 132
A. SCI International Journal Publications 132
B. International Patents 133
C. Domestic Patents 134
D. International & Domestic Conference Papers 136
Chapter 1. Introduction 10
Figure 1.1. Necessity of developing a sustainable energy generation technology without fossil fuel 22
Figure 2.2. Various energy harvesting technologies that convert ambient energy to electricity 23
Figure 3.3. A schematic diagram of triboelectric energy harvesting technology that converts mechanical ambient energy to electrical energy 25
Figure 4.4. A schematic of (a) contact electrification phenomena between different triboelectric materials, (b) working principle of the contact-... 26
Figure 5.5. (a) Theoretical structure of dielectric-to-dielectric contact TEG. (b) Theoretical structure of Metal-to-dielectric contact TEG... 28
Figure 6.6. The four working modes of TEG (a) vertical contact mode, (b) sliding mode, rotation mode, (c) single electrode mode, and (d) freestanding mode 30
Figure 7.7. (a) Electromagnetic wave emitted from daily electronics enter the human body. (b) Electrostatic induction caused by ultralow frequency... 32
Figure 8.8. Surface charge density with (a, b) different work functions, (c, d) internal polarization (low, high) and (e) charge capacity (capacitance) 35
Chapter 2. Metal nanowire-polymer composite layer for surface charge control 11
Figure 2.1. (a) Schematic of fabrication process of AgNW-polymer composite film. (b) OM and (c) SEM images of the AgNWs films prepared using two... 42
Figure 2.2. (a) SEM and (b) AFM images of as-coated AgNW-polymer composite films (left) and embedded AgNW-polymer composite films(right) 43
Figure 2.3. (a) KPFM images of bare PVC film, AgNW-PVC with two different areal factors of AgNWs, (b) KPFM images of AgNW-PMMA with two different... 48
Figure 2.4. (a) Schematic illustration and energy band structure explaining charge transfer and surface potential of AgNW-polymer composite film. The... 50
Figure 2.5. (a) Schematic illustration of contact separation mode TENG based on AgNW-polymer composite film and PFA film. (b) Output voltage and current... 53
Figure 2.6. Results of 3D numerical simulation of potential distribution of TENGs with (a) AgNW–polymer/PFA and (b) AgNW–polymer/nylon... 56
Chapter 3. Self-powered fine dust filtration system using tribo-electrification induced electric field 12
Figure 3.1. (a) Schematic description of the TENG-based fine dust filtration system. (b) Schematic design of the rotation type TENG. (c-d) As fabricated... 67
Figure 3.2. The working mechanism of the TENG. (a) Schematic description of the film-type TENG. (b-e) Schematic illustration showing the suggested... 70
Figure 3.3. SEM images of the friction layers of the triboelectric nanogenerator (scale bar＝2㎛) 71
Figure 3.4. Performance characterization of the rotation-type TENG. (a) The output voltage and current of the TENG as a function of rotation (rpm). (b)... 73
Figure 3.5. Schematically described structure (a) working mechanism of the fine dust filtration system. (b) Illustrations of the TE filter in the fine dust... 75
Figure 3.6. (a) SEM image for PVDF with thickness 7㎛ that were coated on Al plate. The sample were prepared by bar-coating on Al/Si substrate and heat... 76
Figure 3.7. OM images of PVDF coated Al plate after collecting the fine dust. This result shows that PMs of various sizes were... 77
Figure 3.8. COMSOL simulation of the dust collection at the secondary plates of the filter for air filtration. (a) The electric potential in the secondary plates,... 79
Figure 3.9. FEM simulation conditions for collection efficiency of fine dust particles according to surface charge density and flow velocity in the air duct.... 80
Figure 3.10. Performance characterization of TE filter. (a) Performance comparison, in terms of the density of the particles in the filtered air, of the... 83
Figure 3.11. Experimental data of PM2.5 level that were measured by a dust detector. The PM sensor shows that the PM value decreases... 84
Chapter 4. Electrical bandage based on body-coupled energy harvesting for effective electrical stimulation to accelerate wound healing 14
Figure 4.1. Design of the electrical bandage based on body-coupled energy harvesting and the influence on wound healing. (a) Schematic design and... 91
Figure 4.2. Fabrication process of the electrical bandage 93
Figure 4.3. The electrical bandage's AC electrical potential difference over the wound. (a) Schematic working principle of body-coupled energy... 102
Figure 4.4. Digital photographs of the flexible electrical bandage 103
Figure 4.5. Detailed electrical circuit model of electrical bandage 103
Figure 4.6. Theoretically calculated waveform of Vwound[이미지참조] 103
Figure 4.7. High-permittivity P(VDF-TrFE):CCTO nanocomposite which maximize the electric potential difference over the wound. (a) FE-SEM and... 107
Figure 4.8. Materials properties characterization. (a) FT-IR spectra of the P(VDF-TrFE):CCTO nanocomposite at the different CCTO concentrations (0,... 108
Figure 4.9. Relevant cellular activities of human fibroblasts improved by electrical stimulation (ES) and biocompatibility of components. (a) Schematic of... 112
Figure 4.10. Optical microscopy images of the migrating CRL-1502 of the control group (Ctrl.) and stimulated group (Stim.) as obtain by... 113
Figure 4.11. Optical microscopy images of the proliferating CRL-1502 of the control group (Ctrl.) and stimulated group (Stim.) as obtain by... 113
Figure 4.12. Fluorescent image of CRL-1502 on each material(scale bar=200 ㎛) 113
Figure 4.13. The rapid wound recovery by the electrical bandage. (a) Digital photographs of the electrical bandage on the mouse wound model (ES). (b)... 116
Figure 4.14. The relative RNA expression of genes in 7 days wound tissues to β-actin (gene name is above each Figure) 116