Research On Hot Embossing And Manipulator Improvement For Polymer Micro/Nano Fabrication

Hot embossing can replicate Micro/nano scale patterns repeatedly in a large area with reasonable uniformity. As a result, hot embossing has potential applications in obtaining nanostructures and fabricating micro-electromechanical systems (MEMS) with low cost and high throughput. The main research contents in this dissertation are as follows:The experiments of nano grating structure and micron grating fabrication are conducted based on the analysis of hot embossing principle. Then a novel method of hot embossing lithography for multiple nano scale linewidth moulds was experimented. Nano scale grating structures which have from 980nm to 71nm linewidth features were fabricated on the PMMA (polymer methyl methacrylate) film layer with silicon substrate by using the above mentioned. The effects of hot embossing temperature and demoulding temperature on replicating quality of the nano pattern were also discussed in this paper. Experimental results indicate that higher demoulding temperature is more favorable to lessen PMMA leftover from mould and improve the duplication quality. The satisfied duplication quality of multiple nano bar structures can be achieved when both hot embossing temperature is 110℃～125℃and demoulding temperature is 65℃～75℃. Finally, the micron grating was fabricated successfully by improving the hot embossing technic for multiple nano grating structure.Manipulator is one of the important elements for polymer Microfluidic chip fabrication to achieve batch production and automation. Based upon the position control system and force outer loop control method, the force feedback control system which is featured with force outer loop and position loop was described. First, the end effector which is used to implement chip transit was designed and the affection to force measure process caused by friction was also discussed through analyzing simplified mechanical model. Then, with modeling analysis of the force control system, the system observer which can manage force/position control model switching was studied. Finally, the results showed that this force control system for manipulator has a good control precision and repeatability precision besides good adaptability.Reliability design is investigated by researching the collision protection question between manipulator and objects around environment. The collision protection system, which is mainly based on relay and electromagnetic brake, was designed. It can distinguish collision signal and complete protection for manipulator immediately. The position precision affection caused by the protection system was calculated and analyzed. The experimental results show that the inertial displacement can be controlled less than 1mm. The collision protection system has no affection on position precision. It is beneficial for microfluidic chip automated fabrication system to enhance system automation level.