Title Page

Contents

Abstract 17

Chapter 1. INTRODUCTION 19

1.1. Surgical procedures and medical devices 19

1.2. Power sources and triboelectric nanogenerators 23

1.2.1. Power sources of medical devices 23

1.2.2. Triboelectric nanogenerators 26

1.2.3. Ultrasound-driven triboelectric nanogenerators 28

1.3. Bioadhesive devices and triboelectric nanogenerator 31

1.3.1. Bioadhesive devices for wound management 31

1.3.2. Triboelectric nanogenerators for wound management 34

1.4. Body-implantable minimally invasive devices 38

References 42

Chapter 2. Ultrasound-driven bioadhesive triboelectric nanogenerator for instant wound sealing and electrically accelerated healing in emergencies 45

2.1. Abstract 45

2.2. Introduction 46

2.3. Experimental details 50

2.3.1. Fabrication of experimental samples 50

2.3.2. Characterizations 56

2.4. Results and discussion 61

2.4.1. The overview concept and material design 61

2.4.2. The electrical output performance evaluations 63

2.4.3. The evaluations of adhesive performance on wet tissues 69

2.4.4. The in vivo demonstration in acute injuries management 74

2.5. Conclusion 79

References 80

Chapter 3. Ultrasound-Driven Injectable and Fully Biodegradable Triboelectric Nanogenerators 84

3.1. Abstract 84

3.2. Introduction 85

3.3. Experimental details 88

3.3.1. Fabrication of experimental samples 88

3.3.2. Characterizations 93

3.4. Experimental details 100

3.4.1. Fabrication of experimental samples 100

3.4.2. Biocompatible, biodegradable, and electrical properties of materials. 102

3.4.3. Electrical characterizations of I-TENG under PBS 105

3.4.4. Injection process and the in vivo electrical performance 107

3.4.5. The influence of AC electric field (20 kHz) for fibroblast cell migration 114

3.5. Conclusion 118

References 119

Chapter 4. Summary and further work 123

논문요약 125

Chapter 1. Introduction 8

Figure 1.1. Various surgical procedures including strabismus surgery, tendon repair, bone surgery, minimally invasive surgery for internal organs, cosmetic... 21

Figure 1.2. a) Power consumptions of medical devices and an estimation of potential biomechanical energy mapping through the human body. b) Potential... 22

Figure 1.3. a) The Milestones of implantable medical devices over time. b) Various implantable energy harvesters as the power source for medical devices 25

Figure 1.4. Schematic diagram of device structures, and four basic working mechanisms of TENG 27

Figure 1.5. Ultrasound-driven triboelectric nanogenerators for power supply, controllably-degradation and bacterial killing 30

Figure 1.6. The applications of bioadhesives in wound closure, sealing leakage, and immobilization for wound dressing, drug/cell delivery, and fixation of devices 33

Figure 1.7. Applications of nanogenerators for biomedical engineering and healthcare systems 36

Figure 1.8. Triboelectric nanogenerators for wound management 37

Figure 1.9. The wireless technology and minimally invasive medical devices 40

Figure 1.10. Prospects of future medical devices based on implantable energy harvesters 41

Chapter 2. Bioadhesive Triboelectric Nanogenerator for Instant Sutureless Wound Sealing and Electrically-accelerated Healing in Emergencies 9

Figure 2.1. Overview concept and material design of the BA-TENG device for treating acute bleeding wounds. a) Conceptual diagram of BA-TENG for... 49

Figure 2.2. The schematic illustration of the structure, mechanism, and materials of the BA-TENG device. a) Structural schematic of BA-TENG. b) The working... 53

Figure 2.3. a) The chemicals and synthesized procedures for obtaining the novel polycaprolactone-based polyurethane (PCL-r-PU) as the friction layer. b)... 54

Figure 2.4. The Fourier-transform infrared (FT-IR) spectra of PCL-r-PU and PAV. a) The FT-IR spectra of PCL-r-PU, with peaks at 3,350, 1,690, and... 55

Figure 2.5. The MTT assay was used to evaluate the biocompatibility of the newly synthesized PCL-r-PU and PAV films. The results were compared to a... 60

Figure 2.6. Experiment setup and output performance of BA-TENG device under ultrasound (20 kHz). a) Side view of the experimental setup to measure... 66

Figure 2.7. a) KPFM images describing the difference in surface potential of the PCL-r-PU membrane before and after contact with PEDOT:PSS film. b)... 67

Figure 2.8. The triboelectric output performance of BA-TENG measured by pushing tester, and the output voltage (Vpp) was above 119.4 V by contact-...[이미지참조] 68

Figure 2.9. The evaluations of wound sealing and hemostatic control performance of BA-TENG. a) Photographs of immediate wound sealing and... 71

Figure 2.10. Mechanical experiment setups to evaluate the adhesion performance. a) Schematic of the test setup to measure the shear strength of... 72

Figure 2.11. Performance of BA-TENG in the bleeding rat liver incision model. a) Schematics of BA-TENG applied in the bleeding rat liver incision model. b)... 73

Figure 2.12. In vivo demonstration of BA-TENG in acute injuries management in living rats. a) Schematic of BA-TENG in the hemostasis control and... 76

Figure 2.13. The in vivo experimental setup to test BA-TENG's triboelectric output stimulated by ultrasound. a) When the ultrasound was off, BA-TENG... 77

Figure 2.14. In vivo demonstration of BA-TENG in healing acute injuries management in living rats. a) FEM simulation results of E-field provided by... 78

Chapter 3. Ultrasound-Driven Injectable and Fully Biodegradable Triboelec tric Nanogenerators 12

Figure 3.1. Designs and properties of I-TENG driven by ultrasound. a) Schematic illustration of the I-TENG working principle in vivo generated by... 89

Figure 3.2. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectra of PLA showed peaks at 2997 cm¯¹ and 2947 cm¯¹ corresponding... 90

Figure 3.3. The magnesium (Mg) electrode was coated onto a polylactic acid (PLA) substrate. a) The schematic illustration of the size of the Mg electrode... 91

Figure 3.4. The cross-section demonstration of I-TENG. a) The FE-SEM image of the cross-section of the outer layer (PLA film). b) The schematic... 92

Figure 3.5. The real images of accelerated dissolution of biodegradable I-TENG associated with immersion in PBS solution (pH=7.4) at 60 °C 98

Figure 3.6. The MTT assay results of PLA. The MTT assay results of PLA show their biocompatibility compared with the control group without any stimuli 99

Figure 3.7. Biocompatible, biodegradable, and electrical properties of materials. a) The CLSM images to test the cytotoxicity of the I-TENG device. CLSM... 104

Figure 3.8. Electrical characterization of the I-TENG under PBS solution. a) Experiment setup for measuring voltage output of I-TENG under PBS Solution.... 106

Figure 3.9. Injection process and the in vivo electrical performance of I-TENG after inserting to rat leg. a) Illustration workflow of I-TENG after injection. b)... 109

Figure 3.10. The real images of the I-TENG position placed inside the rat legs after injection 110

Figure 3.11. Experimental setup for in vivo tests to measure the output performance of I-TENG inserting into the rat leg (5 mm distance below... 111

Figure 3.12. Experimental setup for ex vivo tests to measure the output performance of I-TENG inserting under porcine (5 mm distance below... 112

Figure 3.13. I-TENG's voltage and current output are driven by ultrasound (20 kHz, 1W cm¯²) placed under porcine 113

Figure 3.14. The influence of AC electric field (20 kHz) for fibroblast cell migration. a) Schematic demonstration of I-TENG's electric field generated by... 116

Figure 3.15. a) Illustrations of the scratch wound healing experiment. Fibroblasts were stimulated for 30 mins every 12 hours (0 hours and 12 hours),... 117