3D Printing System For Biological Materials Based On DMD

With the emergence of 3D printing technology,people's production mode has been gradually changed.In recent years,more and more scholars and researchers begin to study how to apply 3D printing technology in biomedicine.Some traditional 3D printing technologies,such as light curing(SLA),hot-melt deposition(FDM),and selective laser sintering(SLS),can be applied to medical rehabilitation devices and medical models,but for bioactive tissues,the traditional 3D printing technology can't be considered in terms of applicability and precision.Meet the requirements.The emergence of DLP curing technology provides a solution from the fineness and affinity of printing.Based on this,we design and build a bio 3D printing system for basic DLP imaging technology.The main tasks are as follows:1.The paper introduces the principle and development of 3D printing technology,and the research status of biological 3D printing technology at home and abroad.According to the particularity of biological 3D printing,we choose to build a biological 3D printing system based on DLP projection technology.2.The paper introduces the structure of biological 3D printing system built in this paper,and briefly introduces the way to realize 3D printing.This paper introduces the principle of the DLP imaging system based on the 3D printing system,and introduces the working mode of its core device DMD chip,the layout mode and the optical path used.The advantages of 3D printing technology based on DLP imaging system are illustrated for the existing biological 3D printing mode.3.The paper designed.lighting system for 3D printing system.According to the special lighting mode of DMD chip,the energy efficiency and brightness uniformity are taken as the index.Considering the optical expansion of the whole system,the converging lens,square bar,TIR prism and square bar imaging system are designed.And the simulation analysis of the design is carried out.The energy efficiency of the DMD image surface is reached to 89.03%,and the uniformity of the DMD image surface is 89.83%by the 13 point method,which meets the design requirements.4.The paper designed the imaging system for 3D printing system.This chapter describes the analysis of the imaging system to meet the requirements of parameters,such as:magnification,focal length,projection ratio and so on.And the parameters are determined according to the actual demand.In the second part,the design method used in the process of imaging system design and the design process are introduced.After the final design,the point diagram of the imaging system,the MTF transfer function and the distortion of the field are analyzed,and the conclusion is reached to meet the design requirements.5.This paper designed the control system of 3D printing system,including the hardware and software construction of stepper motor control system,the software and hardware construction of DMD control system.The two parts are programmed by Boost library and OpenGL to achieve the desired control effect.6.In the biological 3D printing system,the experimental measurement was carried out.The absorption band and exposure time of the light curing material GelMA were measured.On this basis,the parameters of the control system were adjusted.Finally,according to the pattern projected by DMD,the printing of 3D model is completed.On the imaging surface,when DMD shows the full white picture,the target surface is homogeneously N=89.39%,the average energy density is 15.494mw/cm^2,the total energy of the picture is 136.72mw,the uniformity and power density reach the requirement.Finally,the system is used to complete the 3D printing and get the print sample.