Title Page
Contents
요약문 7
Abstract 9
제1장 Introduction 14
제2장 Preform Preparation 18
제3장 Drawing Process 20
3.1. Materials and Instruments 25
3.2. Diameter measurement 28
제4장 Application 32
4.1. Fiber sensors based on changes in electrical Resistance 32
4.1.1. Design of Fiber sensors based on changes in electrical resistance 35
4.1.2. Material preparation 44
4.1.3. Electrical resistance performance evaluation 48
4.2. STIFFNESS VARIABLE FIBER 53
4.2.1. Design of Stiffness variable fiber 55
4.2.2. Material preparation 58
4.2.3. bending stiffness properties evaluation 60
4.2.4. Validation of device applicability for vascular invasive surgery 67
제5장 Conclusion 71
References 72
Table 1. Evaluate hybrid process feasibility based on materials 27
Table 2. PC+ABS Experimental condition 31
Table 3. Technical Data Sheet for Electrifi conductive Polymer 42
Table 4. Experimental condition for Fiber Sensor 43
Table 5. tensile specimen specification 47
Fig 1-1. Additive manufacturing and thermal drawing process for functional fiber 17
Fig 2-1. FDM 3D Printer with Dual Nozzle 19
Fig 2-2. Preform modeling and output 19
Fig 3-1. Picture of drawing tower 22
Fig 3-2. Compare with cross section (Before) 23
Fig 3-3. Compare with cross section (After) 24
Fig 3-4. PC and PVA material combination (a) FDM printing result (b) Thermal drawing result 26
Fig 3-5. Using PP single material (a) star-shaped cross-sectional shape preform (b) fiber cross-sectional quality 26
Fig 3-6. Compare fiber shrinkage rates (Preform D=25mm, pooling speed 15mm/s) 30
Fig 3-7. Hollow shaped fiber Thickness change with speed 30
Fig 3-8. PC+ABS combination fiber Thickness change with speed 31
Fig 4-1. Idea of Fiber sensors based on changes in electrical resistance 34
Fig 4-2. Early Preform model for Fiber Sensor 37
Fig 4-3. Fiber's cross-section shape from early model (PC+PLA) 37
Fig 4-4. Occurring uneven sections 1 (PC+C-PLA) 38
Fig 4-5. Occurring uneven sections 2 (PC+C-PLA) 38
Fig 4-6. Bad Printing Quality (PC+Copper Polymer) 39
Fig 4-7. Design Preform for increasing the bonding surface of conductive polymer 39
Fig 4-8. Fine Quality of Fiber (PC+C-PLA) 40
Fig 4-9. Picture for Optical microscope (PC+C-PLA) 40
Fig 4-10. Picture for Optical microscope (PC+Copper Polymer) 41
Fig 4-11. Preform design for Increased the proportion of Conductive material 41
Fig 4-12. Fiber's Picture for Optical microscope (PC+Copper polymer) 42
Fig 4-13. DSC Result (Natural PLA) 45
Fig 4-14. DSC Result (conductive PLA) 45
Fig 4-15. Selection Model (ASTM D638-1) 46
Fig 4-16. ASTM D638-1 (Conductive PLA & Natural PLA) 46
Fig 4-17. Tensile test analysis 47
Fig 4-18. The electrical resistance of a fiber over its length (Conductive PLA) 50
Fig 4-19. Electrical resistance value at room temperature (L: 50mm, D: 1.5mm) 50
Fig 4-20. Measure the change in current value as voltage increases 51
Fig 4-21. Change in Electrical Resistance Value with Bend Direction 51
Fig 4-22. Change in electrical resistance as temperature increases 52
Fig 4-23. Idea of Fibers with mechanical anisotropy 54
Fig 4-24. PC+PP Multi-material Preforms Become Fiber 56
Fig 4-25. Post-processing to create channels 57
Fig 4-26. Before & after removing the PP material from the fiber (SEM) 57
Fig 4-27. Measurement and comparison of reaction forces setup equipment 63
Fig 4-28. Comparison of stiffness ratios according to direction between samples 64
Fig 4-29. Graph of Stiffness value comparison according to length change per identical deformation (15 mm samples A) 64
Fig 4-30. Graph of Stiffness value comparison according to length change per identical deformation (15 mm samples B) 65
Fig 4-31. Graph of Stiffness value comparison according to length change per identical deformation (15 mm samples C) 65
Fig 4-32. Graph of Stiffness comparison of measured and interpreted values for the last selected model 66
Fig 4-33. Testing vascularization based on the direction of rotation of the fiber cross-section Setup equipment for vascularization 69
Fig 4-34. (a) Insert horizontal direction (b) Insert vertical direction (c) Insert horizontal-vertical direction 70