| 摘要: | 組織工程為器官和組織的移植提供了替代的方案，隨著積層製造技術的引入，提升了多孔性且外形結構複雜之支架列印的可能性，而本研究選用低溫3D列印技術製作殼聚醣支架。然而，低溫3D列印的沉積面會隨著支架列印高度的增加，與工作平台的距離遠來越遠，導致熱傳導效率降低造成沉積面垂直溫度分布增加。本研究將推導一套能改善沉積面垂直溫度分布的溫控演算法並提升高層數低溫3D列印支架的品質。
本研究改良冷凍循環機的控制模式，將冷凍循環機的外部傳感器安裝於循環塊入口，固定控制點與工作平台間的距離，以便找出感測器間的溫度關係。利用PLA支架分析沉積面溫度與沉積面上方空氣溫度並找出影響材料凝固的關鍵因子為支架沉積面溫度。本研究透過調降冷凍循環機內部循環液溫度來改善沉積面垂直溫度分布，因此測試冷凍循環機最大冷卻效率與計算支架列印時間。最後推導出一套演算法能將列印支架的過程分成數個階段，並計算出每個階段所需列印的層數，同時計算出冷卻循環機啟動的時機。目的在每個階段列印完成後，循環塊入口溫度也能幾乎同時到達冷卻溫度並改善支架沉積面溫度，進而提升殼聚醣支架列印的高度和品質。
最後，由於先前研究使用的殼聚醣材料較難列印高層數支架，為了驗證沉積面垂直溫度分布的改善，利用推導出之溫控演算法製作大尺寸且高層數的殼聚醣支架，並分析凍乾完成後的殼聚醣支架最上層的股線寬度。
;Tissue engineering provides an alternative solution for organ and tissue transplantation. With the introduction of layered manufacturing technology, the possibility of printing porous and complex scaffolds has been improved. In this study, low-temperature 3D printing technology was used to make chitosan scaffold. However, the deposition surface of the low-temperature 3D printing will increase with the printing height of the scaffold, and the distance from the working platform will be farther and farther, resulting in a decrease in the heat transfer efficiency and an increase in the vertical temperature distribution of the deposition surface. This study will derive a temperature control algorithms that can improve the vertical temperature distribution of the deposition surface and improve the quality of high-temperature low-temperature 3D printing supports.
In this study, the control mode of the refrigerated circulators is improved. The external sensor of the refrigerated circulators is installed at the entrance of the coolant enclosure, and the distance between the control point and the working platform is fixed, so as to find out the temperature relationship between the sensors. The PLA scaffold is used to analyze the temperature of the deposition surface and the air temperature above the deposition surface and find out that the key factor affecting the solidification of the material is the temperature of the deposition surface of the scaffold. In this study, the vertical temperature distribution of the deposition surface was improved by reducing the temperature of the circulating fluid in the refrigerated circulators. Therefore, the maximum cooling efficiency of the refrigerated circulators was tested and the printing time of the scaffold was calculated. Finally, a set of algorithms can be derived to divide the process of printing the support into several stages, and calculate the number of layers to be printed in each stage, and at the same time calculate the timing of the start of the refrigerated circulators. Purpose is the inlet temperature of the coolant enclosure can also reach the cooling temperature almost at the same time after the printing in each stage is completed, and improve the temperature of the deposition surface of the scaffold, thereby improving the height and quality of the printing of the chitosan scaffold.
Finally, because the chitosan material used in previous studies is difficult to print high-level scaffold, in order to verify the improvement of the vertical temperature distribution on the deposition surface, a large-size and high-level chitosan scaffold was fabricated using the derived temperature control algorithm. The uppermost strand width of the chitosan scaffold after lyophilization was analyzed. |
