Title Page
Contents
LIST OF ABBREVIATIONS 11
ABSTRACT 12
Ⅰ. INTRODUCTION 14
Ⅱ. MATERIALS AND METHODS 18
2.1. Materials and Pre-step of Hydrogels Fabrication 18
2.1.1. Material Selection 18
2.1.2. Material 20
2.1.3. Sacrificial Layer Manufacturing 21
2.2. Preparation of Hydrogels 22
2.3. Methods to Prove 3D Printability of NIPAM-AAc 25
2.3.1. Theoretical Proof of 3D Printability via Rheological Test 25
2.3.2. Experimental Proof of 3D Printability 28
2.4. pH Responsiveness of NIPAM-AAc According to the v/v ratio of AAc 33
2.5. Swelling Programmable and pH-Responsive Characteristics of NIPAM-AAc 40
Ⅲ. RESULTS 43
3.1. Programmability of Hydrogel Bilayer 43
3.1.1. Experimental Results of Bilayer Thickness 43
3.1.2. Shape Morphing Characteristics of Bilayer 46
3.2. Application 49
3.2.1. Fabrication of the Swelling Programmable and pH-ResponsiveSoft Gripper 49
3.2.2. Actuation of the Gripper via pH 51
Ⅳ. DISCUSSION 54
4.1. pH-Responsive Characteristic of NIPAM-AAc 54
4.2. Difference in Shape Transition of the Soft Gripper and the Bilayer 56
Ⅴ. CONCLUSION 58
Ⅵ. REFERENCES 60
ABSTRACT IN KOREAN 66
Table 1. Nozzle diameter according to the type of Nozzle tip. 30
Table 2. NIPAM-AAc printing condition according to the v/v ratio of AAc. 32
Figure 1. Fabrication of NIPAM and NIPAM-AAc gels. 24
Figure 2. Rheological property test for theoretical proof of printability of NIPAM-AAc. 27
Figure 3. Experimental 3D printability test. 31
Figure 4. 3D printed cylinder-shaped NIPAM-AAc structure (v/v ratio of AAc: 1.24 %). 38
Figure 5. The swelling ratio of NIPAM-AAc by different v/v ratios of AAc. 39
Figure 6. The swelling ratio of the NIPAM-AAc samples with different UV curing times. 42
Figure 7. Selection of bilayer thickness. 45
Figure 8. Bilayer shape morphing characteristic. 48
Figure 9. Gripper design details. 50
Figure 10. Gripper actuation in various pH environments. 53