Title Page
Contents
Abstract 6
국문요약 8
Chapter 1. Introduction 14
Chapter 2. Theoretical Backgrounds 21
2.1. Triboelectric Nanogenerator 21
2.2. Thermionic Emission Model 27
2.3. Activation Energy 30
2.4. Flexoelectric Effect 33
Chapter 3. Relationship of Frictional Heat & Triboelectric Charge 37
3.1. Fabrication & Experiment 37
3.2. Experimental Results 41
3.3. Discussion 65
Chapter 4. Flexoelectrically Augmented Contact Electrification 68
4.1. Fabrication & Experiment 68
4.2. Experimental Results 73
4.3. Discussion 85
Chapter 5. Self-Power Wireless Smart Home Control System 87
5.1. Fabrication & Experiment 87
5.2. Experimental Results 89
5.3. Discussion 98
Conclusion 99
List of Publications 101
Reference 105
Fig. 1. Schematic of current generation for triboelectric nanogenerator. 23
Fig. 2. Schematic Mechanism of sliding mode of TENG 26
Fig. 3. Schematic illustration of charge transfer mechanism. 28
Fig. 4. Example of thermogravimetric(TGA) Data for PDMS polymer. 31
Fig. 5. Schematic of flexoelectic effect when material is (a) bending and (b) normal state 34
Fig. 6. Strain gradient calculation for bending structure 35
Fig. 7. The correlation between frictional force (FF) and loading force (FL) was investigated for blend ratios of 5:1, 10:1, and 30:1.[이미지참조] 39
Fig. 8. Illustration and a photograph of a setup designed to concurrently measure triboelectric charge and temperature for sliding movement. 42
Fig. 9. (a) Synchronization of the IR camera's operation with the sliding machine. (b) Schematic illustrating the measurement of electrical output and... 43
Fig. 10. The simulation results display temperature fluctuations in the case of a 5:1 ratio. These temperature variations escalate in tandem with the... 45
Fig. 11. (a) Young's modulus varies depending on the PDMS ratio. (b) X-ray diffraction patterns of PDMS polymers. (c) Blend ratio dependent crystalline... 46
Fig. 12. (a) Force-distance curves of PDMS for blend ratios of 5:1 and 30:1. (b) Thermal properties influenced by the PDMS ratio. 48
Fig. 13. (a) The density of PDMS varies with the ratio. (b) Surface morphology captured in AFM images. (c) The dielectric constant is... 49
Fig. 14. (a) Time-dependent variation in triboelectric charge during sliding. (b) Temperature fluctuations of PDMS over sliding time for different... 51
Fig. 15. Comprehensive infrared (IR) images of PDMS illustrating different blend ratios and varying sliding durations. 52
Fig. 16. (a) Correlation between triboelectric saturation charge and charged time-constant, and (b) association between variation of triboelectric... 54
Fig. 17. (a) The thermogram obtained during thermogravimetric analysis heating. (b) Curves obtained from fitting the Coats and Redfern equation... 56
Fig. 18. Si 2p peak intensity at the FTO glass for different (a) blend ratios and (b) sliding times in X-ray photoemission measurements. The Si 2p peak... 59
Fig. 19. Surface morphology of PDMS observed through optical microscopy and atomic force microscopy for blend ratios of (a) 5:1, (b) 15:1, and (c) 30:1... 60
Fig. 20. (a) Photoemission spectra of Si 2p and O 1s were obtained for PDMS in both flat and rough regions. (b) Atomic ratios of C/Si and O/Si were... 62
Fig. 21. (a) Relationship between PDMS bond rupture, temperature variations in FTO glass and PDMS relies on the activation energy. (b)... 63
Fig. 22. Digital images of (a) customized alumina holder and (b) experimental setup with vertical guides. 70
Fig. 23. Digital image of customized bending system for KPFM measurement. 71
Fig. 24. (a) Crystalline structure and AFM surface morphology of 2D layered mica. (b) Rietveld refinement result by single crystal XRD (c) Photographs... 74
Fig. 25. Schematic illustration of triboelectric properties at bent mica. 77
Fig. 26. (a) High-resolution X-ray diffraction (HR-XRD) patterns illustrate the structural differences in crystalline mica. (b) Raman-active phonon... 79
Fig. 27. Current output of mica films (a) bending process and (b) without contact approach-recede process. The schematic representation depicted the... 80
Fig. 28. Calculation by density functional theory (DFT) for (a) density of states about flat mica and (b) band gap (Eg) and effective mass of electron...[이미지참조] 81
Fig. 29. Triboelectric charge output of a MF-TENG depend on (a) Strain-gradient and (b) thickness of mica. (c) Schematic band diagrams between Al... 83
Fig. 30. (a) Photograph of vertical MF-TENG. (b) Diagram illustrating the self-powered wireless communication system. 88
Fig. 31. Triboelectric charges and currents depend on (a) Film size, (b) applied pressure, (c) contact material, (d) operation cycle, and (e)... 90
Fig. 32. (a) Diagram illustrating the vertical MF-TENG for wirelessly controlling various smart home appliances from outdoors. (b) Photograph... 92
Fig. 33. Real-time Bluetooth communication displaying finger positions, the "FLEXO" alphabet letters on LCD panel, and voltage profiles. 94
Fig. 34. (a) A diagram depicting multiple functions assigned to specific numbers in Arduino for various appliances. (b) Images demonstrating... 95