| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 96 === In the previous Dynamic Mask Rapid Prototyping System developed in our laboratory, PCL-PEG-PCL was mixed with PEG-HEMA in chloroform and cured to create scaffolds successfully. However, the solubility of PEG-HEMA in chloroform is still an issue to be improved. Besides, the old system could not create scaffolds more than 5 layers without pore closure. Therefore, in this research, PEG-HEMA synthesis and the system were improved. Moreover, thicker and more precise 3D scaffolds were fabricated.
In PEG-HEMA synthesis, 98% HEMA was used to replace 96% HEMA. The new PEG-HEMA can be dissolved completely in not only chloroform but also other solvents, such as acetone. The re-dissolution issue of PEG-HEAM and cured PCL-PEG-PCL was also improved. Besides, the structure of the system was redesigned to provide stability and a DLP projector was adopted directly to replace the assembled dynamic mask generator. The new system was capable of providing better mask images and performance.
In 3D porous scaffold fabrication, the achievable layers and results were better than the old system, but due to the reflection of previous cured layers, over-cure happened and pores may be closed after 6 layers. Three approaches were tested to solve this problem—decreasing the curing time of later layers, decreasing the scaffold dimensions of later layers for compensation, and assembling basic scaffold sets. As a result, assembling basic scaffold sets was the best among three and could reduce the scaffold dimension error effectively from 40% to 5.6% for a 6-layer scaffold. With this assembly strategy, it is possible to fabricated thick and precise 3D scaffolds without pose closure problem.
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