Advanced Materials Research Vols. 403-408

Abstract: In this article, we described a rapid and low-cost method to fabricate polystyrene molds for PDMS microfluidic devices using a CO₂ laser system. It takes only several minutes to fabricate the polystyrene mold with bump pattern on top of it using a CO₂ laser system. The bump pattern can be easily transferred to PDMS and fabricate microchannles as deep as 3µm on PDMS.

Abstract: The tensile shear loads in resistance spot welding of TC4/AZ31B with addition Al power have been investigated in this paper. The results showed that the tensile shear loads with and without addition Al power were 2.636 KN and 3.692 KN when welding current was 9800A , respectivly. And the values changed 2.971 KN and 4.167 KN when the welding current was 11300A, respectively. Morphology characteristics of the welding zone were studied by scanning electron microscopy (SEM), energy dispersive spectrometer (ESD). The results suggested that the addition of Al power on the sheets of TC4 and AZ31B increased much in the tensile-shear loads when welding TC4 and AZ31B by RSW.

Abstract: After discussing the technology of electronic Kanban, simulation annealing algorithm is introduced to determine the number of Kanbans and lot sizes of part types under the environment of variant demand, stochastic processing times and different types of products. Also a newly developed Kanban system is presented to dynamically and timely adjust the number of Kanbans in order to offset the blocking and starvation caused by surging demands and stochastic processing times. A simulation model of Kanban system is built to verify the various performances of electronic Kanban and traditional one. At last the performance differences in order completion and average inventory level between the number-fixed Kanban system and the number-adjustable one are presented and verified.

Abstract: Magnesium alloy, differential temperature drawing, mould structure, surface roughness Abstract. To improve the formability of magnesium alloy sheet, the differential temperature drawing process was presented, and the mould structure of differential temperature drawing process for magnesium alloy was well-designed and fabricated by analyzing the friction and the stress distribution of material in drawing process. With the blank heated to 200-235°C at the flange by inserting heating coils and thermocouples in die and binder and the drawn cup cooled by injecting cooling water into die and punch, the differential temperature drawing process of magnesium alloy sheet was performed successfully and the value of surface roughness Ra1.6um was adopted for punch, Ra0.4um was adopted for die and binder. The result shows that by using the designed mould, the deep drawing performance of AZ31B magnesium alloy can be enhanced obviously and the value of LDR can be increased form 2.1 to 3.05.

Abstract: In order to improve the machining efficiency of the duralumin turbine rotor of maglev molecular pump, this paper proposes a new double-spindle horizontal milling machining center structure. Through a brief introduction to other types of machine tools, describes the characteristics of this new machine tool and symmetrical machining implementation. This paper proposes a new double-spindle horizontal milling machining centers so that the machining efficiency of duralumin turbine rotors is improve 100% more than that of the traditional machine tool in theory. Moreover, its machining accuracy get relative improve as the decrease of the dividing accumulative error. At the same time, the cost of workpiece is reduced greatly.

Abstract: According to sensitive structure of vector hydrophone which imitates fish lateral line cells, a novel encapsulation of polyurethane is proposed, that is, using polyurethane, the same material as sound-transparent cap, instead of castor oil to package. It is desirable that the novel encapsulation may effectively solve the problem of vector hydrophone’s low sensitivity. On the basis of analysis theoretical model of sound-transparent cap’s three layer mediums, this paper simulated the whole encapsulation structure by ANSYS. It can be concluded that the sensitivity is 0.267mV/Pa, resonance frequency is 1151.37 Hz. Finally, the prototype of the vector hydrophone was fabricated and preliminary characterization tests of the hydrophone were performed. Results show that the novel encapsulation hydrophone possesses satisfactory directional pattern and the free-field voltage sensitivity is -188.9 dB, which is 8.8dB higher than castor oil encapsulation.

Abstract: Due to the complicated behavior of the dispensing fluid and have no effective method to measure the micro-fluid value dispensed online, controlling the micro-fluid dispensing process has proven to be a challenging task in achieving a high degree of consistency in the amount of fluid dispensed. To enhance the dispensing performance and get a high consistency, this paper presents the development of a model for prediction the amount of fluid dispensed. Based on the model, a vision based control strategy is then developed to improve the consistency in the amount of fluid dispensed. Experiments were conducted to verify the effectiveness of the control strategy.

Abstract: A novel double liquid lens based on Electrowetting-On-Dielectric (EWOD) is presented and analyzed. The special construction is that the lens was divided into four quadrants. The particular fabrication process is presented to achieve the structure. It was proved that the lens not only expressed the electric zoom character but also shifted focal point away from optical axis. It also achieved an infinite focal length under zero electric field. The paper presented the relationship between the focus length and applied voltage, also gave the association between focus length and the applied voltage from 0V to 80V. We analyzed how the optical axis shifted according to the voltage difference between quadrants, furthermore, explained the new function that the focus object was away from center of lens.

Abstract: In this paper, Methods of SOC estimation of Extended Kalman Filter (EKF) is studied based on the characteristics of Nickel-Metal Hydride (Ni-MH) battery pack with 120 cells in series and 8Ah capacity for HEV. In the study of EKF-based SOC estimation, the improved Thevenin circuit model is adopted, and a new hybrid pulse power characterization （HPPC） test is designed to identify the model parameters by using piecewise linear regression method. In this way, the precision of the circuit model is improved. In addition, The Kalman gain matrix is optimized for EKF iterative algorithm by two ways: a constant gain is increased taking into account the entire process; a dynamic gain which increases at the beginning of abrupt change and decreases rapidly after abrupt change is set up. The improvement achieves a good tracing prediction.

Abstract: Silicon-on-insulator (SOI) is becoming more attractive as a photonic material for photonic integrated circuits (PLC) because of its unique features. In this paper, we modeled and simulated the performance of the SOI phase modulator with various doping configuration based on the plasma dispersion effect. The effect of the free injected carrier in the region of the propagating optical mode have been investigated at the optical wavelength of 1.55µm. The proposed device have been integrated in the SOI rib waveguide with trapezoidal cross section structure and four different doping configurations have been chosen which are the n⁺p⁺n⁺, p⁺n⁺p⁺, n⁺n⁺p⁺ and the p⁺p⁺n⁺. Our results show that the n⁺n⁺p⁺ configuration possessed the best modulation efficiency of 0.026V.cm and gained the smallest absorption loss of 1.1dB at 0.95V applied voltage.