Research On Hot Embossing Technique And Theory For Fabrication Of Polymer Microfluidic Chips

Microfluidic chip technology is a new territory in the new century, it is the frontier of analytical sciences, micro electromechanical process, life sciences, chemosynthesis, analytical instrument and environmental sciences etc. Hot embossing is an important method to fabricate polymer microfluidic chip, it has certain advantages such as high replication precision, low stress, low cost and simple process, In this paper, hot embossing and thermal bonding techniques for fabricate polymer microfluidic chip have been studied, polymer hot embossing theory and simulation have also been investigated.The major work on hot embossing and thermal bonding experiments have been done as follows:Hot embossing experiments were carried out to understand process parameters influence on microchannel filling, process parameter including temperature, holding time and pressing pressure. According to changed temperature quasi creep experiments, the hot embossing reference temperature of a certain polymer was determined. The microchannel incomplete filling and inconsistent of depth were solved by optimizing process parameters.Bonding of polymer microfluidic chips was carried out with PMMA, COP480 and COP1020. The incomplete bonding and microchannel distortion were solved, and we got high quality microfluidic chip.Finite element software, MSC.Marc, was used to simulate the hot embossing process, theory and simulation researches were done as follows:Viscoelastical behavior of polymers near their glass transfer temperatures was studied by compression creep tests. Polynomial, first order decay exponential and wide kelvin-vogit models were used to fit material creep curves.Comparing the results of the simulation with creep and viscoelastic material models, viscoelastic model was chosen for hot embossing simulation. The wide kelvin-vogit viscoelastic model was used to simulate the influence of temperature and time to polymer filling. Hot embossing experiments were done to validate the simulation results. The results of experiment and simulation have good consistence, it showed that the finite element analysis can be used to instruct experiment.