Title Page
Abstract
국문 요약
Contents
Chapter 1. Introduction 17
1.1. Research Background 17
1.1.1. Electrochemical polishing 19
1.1.2. Biocompatibility 21
1.1.3. Biomedical Metals 22
1.2. Purpose of Research 26
Chapter 2. Optimal Electrochemical Polishing condition 28
2.1. Electrochemical Polishing Process Factors 28
2.2. Experiments by Process Factors 30
2.2.1. Experiments and Results by Electrolyte Composition 30
2.2.2. Experiments and Results by machining time 38
2.2.3. Experiments and Results by Applied Current Amount 46
Chapter 3. Mechanical Properties of Biomedical Metals 54
3.1. Surface Roughness 54
3.1.1. Surface Roughness Experiment 55
3.1.2. Surface Roughness Experiment Results 56
3.2. Contact Angle 60
3.2.1. Contact Angle Experiment 61
3.2.2. Contact Angle Experiment Results 62
3.3. Residual Stress 66
3.3.1. X-ray Diffraction Experiment 67
3.3.2. X-ray Diffraction Experiment Results 68
Chapter 4. Biocompatibility of Biomedical Metals 72
4.1. Blood compatibility 72
4.1.1. Blood Contact Angle Experiment 73
4.1.2. Blood Contact Angle Results 74
4.2. Cytotoxicity 79
4.2.1. MTT assay 80
4.2.2. MTT assay Results 82
4.3. Antithrombotic 90
4.3.1. Blood Clot Experiment 90
4.3.2. Blood Clot Experiment Results 92
Chapter 5. CONCLUSION 95
REFERENCES 99
Table 2.1. SUS316L electrochemical polishing experimental conditions 31
Table 2.2. Nitinol electrochemical polishing experimental conditions 31
Table 2.3. SUS316L Experiment Condition of electrolyte composition 33
Table 2.4. Nitinol Experiment Condition of electrolyte composition 36
Table 2.5. SUS316L Experiment Condition of machining time 39
Table 2.6. Nitinol Experiment Condition of machining time 39
Table 2.7. SUS316L Experiment result of machining time 41
Table 2.8. Nitinol Experiment result of machining time 44
Table 2.9. SUS316L Experiment Condition of applied current 47
Table 2.10. Nitinol Experiment Condition of applied current 47
Table 2.11. SUS316L Experiment result of applied current 49
Table 2.12. Nitinol Experiment result of applied current 52
Table 3.1. Result of SUS316L Contact angle experiment 62
Table 3.2. Result of Nitinol Contact angle experiment 64
Table 3.3. SUS316L properties 68
Table 3.4. SUS316L residual stress 69
Table 3.5. Nitinol properties 70
Table 3.6. Nitinol residual stress 71
Table 4.1. Blood contact angle experimental conditions 73
Table 4.2. Comparison of SUS316L blood contact angles before and after EP 75
Table 4.3. Comparison of Nitinol blood contact angles before and after EP 77
Table 4.4. MTT assay experimental conditions 81
Table 4.5. SUS316L MTT assay Result 83
Table 4.6. Nitinol MTT assay Result 87
Table 4.7. Blood clot experimental conditions 91
Fig. 1.1. Current density-voltage curve of electrochemical polishing 20
Fig. 2.1. Schematic diagram of electrochemical polishing process 29
Fig. 2.2. Electrochemical polishing process 29
Fig. 2.3. Comparison of SUS316L surface roughness over time of electrolyte composition 33
Fig. 2.4. SUS316L Type 1 result (50:30:20 composition) 34
Fig. 2.5. SUS316L Type 2 result (30:50:20 composition) 34
Fig. 2.6. SUS316L Type 3 result (10:50:40 composition) 34
Fig. 2.7. Comparison of Nitinol surface roughness over time of electrolyte composition 36
Fig. 2.8. Nitinol Type 1 result (90:10 composition) 37
Fig. 2.9. Nitinol Type 2 result (80:20 composition) 37
Fig. 2.10. Nitinol Type 3 result (70:30 composition) 37
Fig. 2.11. Comparison of SUS316L surface roughness over machining time 41
Fig. 2.12. SUS316L experiment result by machining time (a) 60sec, (b) 180sec, (c) 300sec (d), 420sec (e) 540sec 42
Fig. 2.13. Comparison of Nitinol surface roughness over machining time 44
Fig. 2.14. Nitinol experiment result by machining time (a) 30sec, (b) 60sec, (c) 90sec (d), 120sec (e) 150sec 45
Fig. 2.15. Comparison of SUS316L surface roughness over applied current 49
Fig. 2.16. SUS316L experiment result by appiled current (a) 1A, (b) 3A, (c) 5A, (d) 7A, (e) 9A 50
Fig. 2.17. Comparison of Nitinol surface roughness over applied current 52
Fig. 2.18. Nitinol experiment result by appiled current (a) 1A, (b) 2A, (c) 3A, (d) 4A, (e) 5A 53
Fig. 3.1. 3000x SEM image Before EP 57
Fig. 3.2. 15000x SEM image Before EP 57
Fig. 3.3. 3000x SEM image After EP 57
Fig. 3.4. 15000x SEM image After EP 57
Fig. 3.5. Average roughness of SUS316L 57
Fig. 3.6. 3D photograph of SUS316L 57
Fig. 3.7. 3000x SEM image Before EP 59
Fig. 3.8. 15000x SEM image Before EP 59
Fig. 3.9. 3000x SEM image After EP 59
Fig. 3.10. 15000x SEM image After EP 59
Fig. 3.11. Average roughness of Nitinol 59
Fig. 3.12. 3D photograph of Nitinol 59
Fig. 3.13. Contact angle 60
Fig. 3.14. Contact Angle of SUS316L Before EP 63
Fig. 3.15. Contact Angle of SUS316L After EP 63
Fig. 3.16. Contact Angle of Nitinol Before EP 65
Fig. 3.17. Contact Angle of Nitinol After EP 65
Fig. 3.18. Bragg's Law 66
Fig. 3.19. SUS316L sin²Ψ - 2θ graph Before EP 69
Fig. 3.20. SUS316L sin²Ψ - 2θ graph After EP 69
Fig. 3.21. Nitinol sin²Ψ - 2θ graph Before EP 71
Fig. 3.22. Nitinol sin²Ψ - 2θ graph After EP 71
Fig. 4.1. SUS316L Blood Contact Angle result graph 75
Fig. 4.2. Blood Contact Angle of SUS316L Before EP 76
Fig. 4.3. Blood Contact Angle of SUS316L After EP 76
Fig. 4.4. Nitinol Blood Contact Angle result graph 77
Fig. 4.5. Blood Contact Angle of Nitinol Before EP 78
Fig. 4.6. Blood Contact Angle of Nitinol After EP 78
Fig. 4.7. Schematic diagram of MTT assay experiment 81
Fig. 4.8. SUS316L MTT assay result graph 83
Fig. 4.9. Day 1 of Cell culture on SUS316L 84
Fig. 4.10. Day 2 of Cell culture on SUS316L 84
Fig. 4.11. Day 3 of Cell culture on SUS316L 85
Fig. 4.12. Day 4 of Cell culture on SUS316L 85
Fig. 4.13. Nitinol MTT assay result graph 87
Fig. 4.14. Day 1 of Cell culture on Nitinol 88
Fig. 4.15. Day 2 of Cell culture on Nitinol 88
Fig. 4.16. Day 3 of Cell culture on Nitinol 89
Fig. 4.17. Day 4 of Cell culture on Nitinol 89
Fig. 4.18. Schematic diagram of blood clot experiment 91
Fig. 4.19. SUS316L with PRP Before EP 93
Fig. 4.20. SUS316L with PRP After EP 93
Fig. 4.21. Nitinol with PRP Before EP 94
Fig. 4.22. Nitinol with PRP After EP 94