Experimental And Simulation Study Of UV Curing Injection Molding For Microfluidic Chip

In this paper, a new fabrication method of micro fluidic chip -UV curing micro injection molding is introduced. This method uses the liquid UV curing material instead of traditional thermoplastic polymer and glass and silicon, has the characteristics of energy saving and environmental protection; UV curing molding method instead of etching, heat-die pressing process, molding, laser engraving method and other traditional forming methods. At the same time this paper developed a method of photochemical sealed chip in the die. The whole process can meet the requirement of chip mass production, and because the characteristics of injection pressure, holding pressure required is small and no plasticization required, the molding equipment is simple, the production cost is reduced;the molding cycle is greatly shortened than the traditional processing method. The most research in this paper has done as follows :Designed and manufactured a set of experimental equipment of UV curing micro injection molding, compared with the previous work, this paper designed a mold which can realize the function that product ejection and open the die at the same time, not only greatly save the space,but also meet a more important requirement: the whole process of mold filling and curing can be observed and recorded. The material can be evacuated in the injection cylinder, ensure the material is fully defoaming;heating and holding device is added on the injection cylinder; the diameter of the injection cylinder is calculated according to the volume of the cavity, injection stroke is more reasonable; the scanning line source illumination mode improved the forming efficiency and the forming accuracy.2. The mechanical properties of different formulations were studied,and the effects of molding parameters (injection pressure, light power,illumination mode) and formulas (monomer kinds and monomer content)on the molding efficiency were studied. With the increase of monomer content, injection pressure, light power the processing efficiency is improved, and the illumination mode of plane irradiation also can improve the processing efficiency; the final forming time can be controlled within one minute, compared with the traditional molding method, the molding cycle is greatly shortened. With the content of TMPTA's increase the strength, elastic modulus, hardness of products are improved, with the content of EOEOEA's Increase the strength, elastic modulus, hardness of products are reduced, with the content of TMPTA ever EOEOEA's increase the elongation of products is decreased.3. Used the mold designed in this paper and the other a simple mold,by mean of visualization, the forming process of the product is recorded and analyzed, the mechanism of forming defects is analyzed, and the improvement methods of changing the filling mode and improving the light source irradiation head are put forward, the defects can be completely eliminated, products with good forming quality are obtained.4. A series of tests were carried out on the products (such as the integrity of the flow channel, the hydrophilicity and the light transparency). The results showed that flow channel of the chip was good,the product was hydrophilic, and the transmittance was good. Using COMSOL Multiphysics simulation software to simulate the chip model,the process parameters in which can generate droplets are obtained, the process parameters of simulated were carried out in the experiment to verify the function of the chip, we find droplets can be generated in the microfluidic chip processed through the method which is put forward in this paper.