Technical Study Of High Precision Composite Printing Of Synthetic Polymer And Hydrogel

In recent years,with the rapid development of tissue engineering,it is urgent to construct tissues and organs with good complex mechanical properties and bioactivity in vitro,which puts forward higher requirements for the development of multi-nozzle biological 3D printing technology,especially in Print precision,precise start-stop control and cell survival rate made greater progress.Therefore,the development of multi-nozzle biological 3D printing system and related equipment,to explore multi-nozzle composite printing technology will become the biological 3D printing technology in the field of tissue and organ manufacturing can be widely used in the key.In this paper,multi-nozzle biological 3D printing applications in the composite tissue as the research objective,has set up a multi-nozzle biological 3D printing system and the key components of the design and development.In this paper,different biological 3D printing methods were analyzed.The squeeze push rod extrusion method was selected as the 3D printing mode,and the flow channel of the nozzle cavity and the nozzle was optimized.I developed the temperature and humidity of the molding room Control system based on the semiconductor refrigeration technology.According to the requirement of scaffolds during the construction of composite tissue,the preparation scheme of PCL+TCP composite was proposed.A high precision composite material mixing device was designed based on the characteristics of the two materials and the preparation requirements of composite materials.I completed the development of the CAD / CAM system and the three-dimensional model of composite print and print trails and so on have been optimized based on topology reconstruction algorithm,CLI layered algorithm and trajectory optimization algorithm.The key issues which affected composite printing were explored.First of all,two methods of precise start-stop control of composite printing based on software control and hardware control were put forward.The control algorithm and hardware structure were optimized in an innovative way,and the interrelationship and disposition of each amount were clarified through experiments.Seconds,I Introduced the effect of the strength of synthetic polymer scaffold on the performance of the overall scaffold,the fusion bonding mechanism of composite polymer materials was analyzed and the key factors affecting the bond strength of scaffolds were analyzed;Finally,I explored the thermal effects of the composite printing process and the real-time monitoring system of composite temperature zone and microstructure was set up to detect the molding temperature zone and the shape of the stent in the printing process.I summarized the influences of various factors on the cell survival rate based on the test results.In this paper,I completed the construction of composite structure with PCL+TCP composites and gelatin/sodium alginate solution contains hepatocyte based on the investigation of the composite printing system and the key process parameters.I explored the best ratio of PCL to TCP in composites.I analyzed the viscosity characteristics of gelatin and the effect of sodium alginate on the viscosity of gelatin.I constructed a biologically complex biological structure with a complete structure and relatively accurate dimensions,and performed in vitro culture on the composite biological structure.The stability of the composite printing system and the printing process was verified.Through this project,we completed the construction of high-precision biological compound printing system and provided the basic platform for the construction of complex tissues and organs.For the first time,the in-depth research on composite printing technology of high and low temperature materials has provided valuable experience for subsequent tissue and organ regeneration in vitro,at the same time which laid the foundation for the further development of tissue engineering.