High-precision 3D Printing Based On DLP Technology And Its Application In Microfluidics

In recent years,with the increasing print accuracy and speed of 3D printing technology,3D printing combined with microfluidic application has attracted more and more attention.Compared with conventional 3D printing technology,Digital light processing(DLP)3D printing has obvious advantages in print accuracy and speed.However,the current commercial DLP 3D printer has a large printing target,but the XY axis printing precision is generally more than 100 ?m,which is not suitable for the fabrication of microstructure.In this paper,a high-precision 3D printing system is designed and built.The system includes a microscope projection optical system and a conjugate designed real-time focus detection system,it's single exposure area is about5 mm × 3 mm,and its optical resolution can reach 4 ?m,when PEGDA photosensitive material is used for printing,the actual printing accuracy of20 ?m in XY direction can be achieved.In order to meet the needs of large area printing,a high-precision three-axis motion system is developed,which can achieve accurate focusing and target stitching.Among them,by precisely controlling the movement of XY axis displacement platform for target stitching,according to the range of the motion system,the stiching target surface of 50 mm × 50 mm can be realized.In this paper,a stitched helical structure is completed by using this system,and the stitched target is about 10 mm × 6 mm.In order to meet the needs of 3D printing system and its application in microfluidic field,the supporting software integrated with optical projection control and high-accuracy motion control function is developed,which can meet the needs of rapid fabrication of large-area microstructure.By using the 3D printing system,a novel rapid manufacturing process for microfluidic mold is developed,which has the advantages of fast time,low cost and non-toxic.In order to test the feasibility of the process,we made a microfluidic chip for droplet generation,and completed the droplet generation test using the fabricated droplet generation chip.In order to verify the feasibility of the system in the direction of biological 3D printing,PEGDA and Gel MA were printed by this system,this two kinds of hydrogel are commonly used in organ chips field.The PEGDA hydrogel has been used to complete the fabrication of hydrogel microstructure,the accuracy of PEGDA microstructure can reach 20 ?m.The printing and 3D culture of HL7702 and HEK-293 cells were completed by using Gel MA hydrogel,among them,HL7702 cells could be cultured for one week after printing.The 3D printing system provides a new technical route for microfluidic chip fabrication and organ chip printing in the future.