Mechanical System Design Of Extruded Biological 3D Printer And Experimental Research

With the complication of printed objects,bio 3D printing is moving in the direction of multi-material printing,better printability,and higher cell survival.This paper mainly studies the calculation and optimization of flow path shear stress distribution based on extrusion bio-3D printer,the development and improvement of multi-material printing nozzle,and explores the change rule of printability of gelatin aqueous solution with dynamic viscosity as the core.Establish a shear stress calculation model in the flow path.In the flow channel simulation calculation during the print head design process,the shear stress distribution was printed and compared when printing the same material under different flow path shapes.A parametric model for the calculation of shear stress for different printed materials and different shapes of flow paths is given.Determine the flow path that is optimized for sizing conditions and guide the printhead design.The printing material flow test is designed to simplify and transparentize the extrusion printing process,and the interface material method is used to study the flow characteristics of the printed material to verify the correctness of the simulation calculation.Develop multi-material printers for continuous co-printing.In response to the development needs of bio 3D printing,a multi-material sequential co-point printing process and apparatus based on extrusion bio 3D printing technology was developed.The mechanical system of the device mainly includes a printing platform and a printing nozzle.This design completes the scheme design,simulation calculation,structural design and final construction of the 3D printing platform.Based on the experimental research,the scheme of continuous co-point printing is realized,and the equipment is improved based on this printing scheme to reduce the degree of intrusion between materials.A test study on the printability of aqueous gelatin solution was carried out.Investigate the printability of 10%,15%,20% gelatin aqueous solutions at different temperatures,test the rheological properties of materials,and dig deep into the essential reasons for the influence of temperature concentration on printability,and summarize the power suitable for printing.Viscosity area.This paper develops extruded bio-3D printing equipment based on flow field simulation,and conducts material switching,fluid flow and printing molding experiments.