In order to use micro ultrasonic bonding technique to package polymer microfluidic chips, an auxiliary microstructure named micro energy director is designed and fabricated. The hot embossing process for PMMA （ polym...In order to use micro ultrasonic bonding technique to package polymer microfluidic chips, an auxiliary microstructure named micro energy director is designed and fabricated. The hot embossing process for PMMA （ polymethyl methacrylate） substrates with both concave micro channel and convex micro energy director for ultrasonic bonding is studied. The embossing processes with different embossing temperatures are simulated using Finite Element Method （FEM）. The optimized parameters are： the embossing temperature of 135 ℃ , holding time of 200 s, and the embossing pressure of 1.65 MPa. The experimental results show that the replication error between experiments and simulations is less than 2% and the replication accuracy of the microstrueture is more than 96%. The study offers a method for quick optimizing parameters for hot embossing both concave and convex microstructures.展开更多
Methods for evaluating the resistance to cathodic disbondment （RCD） of anti-corrosion coatings on buried pipelines were reviewed. It is obvious that these traditional cathodic disbondment tests （CDT） have some dis...Methods for evaluating the resistance to cathodic disbondment （RCD） of anti-corrosion coatings on buried pipelines were reviewed. It is obvious that these traditional cathodic disbondment tests （CDT） have some disadvantages and the evaluated results are only simple figures and always rely on the subjective experience of the operator. A new electrochemical method for evaluating the RCD of coatings, that is, the potentiostatic evaluation method （PEM）, was developed and studied. During potentiostatic anodic polarization testing, the changes of stable polarization current of specimens before and after cathodic disbonding （CD） were measured, and the degree of cathodic disbondment of the coating was quantitatively evaluated, among which the equivalent cathodic disbonded distance AD was suggested as a parameter for evaluating the RCD. A series of testing parameters of the PEM were determined in these experiments.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.50975037)the State Key Development Program for Basic Research of China(Grant No.2011CB013105).
文摘In order to use micro ultrasonic bonding technique to package polymer microfluidic chips, an auxiliary microstructure named micro energy director is designed and fabricated. The hot embossing process for PMMA （ polymethyl methacrylate） substrates with both concave micro channel and convex micro energy director for ultrasonic bonding is studied. The embossing processes with different embossing temperatures are simulated using Finite Element Method （FEM）. The optimized parameters are： the embossing temperature of 135 ℃ , holding time of 200 s, and the embossing pressure of 1.65 MPa. The experimental results show that the replication error between experiments and simulations is less than 2% and the replication accuracy of the microstrueture is more than 96%. The study offers a method for quick optimizing parameters for hot embossing both concave and convex microstructures.
基金This work is financially supported by the National Natural Science Foundation of China (No.2992021).
文摘Methods for evaluating the resistance to cathodic disbondment （RCD） of anti-corrosion coatings on buried pipelines were reviewed. It is obvious that these traditional cathodic disbondment tests （CDT） have some disadvantages and the evaluated results are only simple figures and always rely on the subjective experience of the operator. A new electrochemical method for evaluating the RCD of coatings, that is, the potentiostatic evaluation method （PEM）, was developed and studied. During potentiostatic anodic polarization testing, the changes of stable polarization current of specimens before and after cathodic disbonding （CD） were measured, and the degree of cathodic disbondment of the coating was quantitatively evaluated, among which the equivalent cathodic disbonded distance AD was suggested as a parameter for evaluating the RCD. A series of testing parameters of the PEM were determined in these experiments.
