| dc.description.abstract | 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. | en_US |