Table of Content

30 November 2011, Volume 45 Issue 11 Previous Issue    Next Issue

Mechanical Engineering

Select

Friction and Wear Behavior of Organic Silane /Rare Earth Self-assemblied Composite Film on Silicon 2011, 45 (11):  1577-1580.  Abstract ( 3944 )   Save The composite film of nanometer rare-earth/silicon coupling reagent MPTS-MPTES was prepared on the hydroxylated single-crystal silicon substrate by a self-assembling process from specially formulated solution. The resultant composite film was characterized by means of atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). The contact angles of distilled water on the silane SAMs and the composite film were measured to compare the surface states. The tribological properties of the films sliding against GCr15 steel ball were evaluated on a DF-PM static-dynamic friction and wear tester. The experimental results show that rare earth (RE) can be easily incorporated in the MPTS-MPTES SAMs and lead to changed surface state of the composite film. Moreover, MPTS-MPTES / RE composite film is effective in reducing friction and resisting wear compared with MPTS-MPTES SAM as it slides against the steel counterpart at a small load, indicating its promising applications in microelectromechanical system (MEMS) field.   References | Related Articles | Metrics

Select

Grey Neural Network Modeling for Machine Tool Thermal Error 张毅,杨建国 2011, 45 (11):  1581-1586.  Abstract ( 3884 )   Save This paper proposed a new model of prediction on thermal error of machine tools based on grey neural network combining the data processing merits of grey model and artificial neural network, respectively. The new model can be classified into two forms——parallel grey neural network (PGNN) and inlaid grey neural network (IGNN). The former is to predict the thermal error with optimal linear combination of the result from grey model and artificial neural network respectively, while the weight value of this model is subject to the required accuracy of the experiment. The latter is to optimize the topological structure of the neural network by adding a grey layer before the input layer and a white layer after the output layer, so as to reduce the randomness of the original data and enhance the robustness and the fault tolerant ability. Compared with the traditional grey model and the artificial neural model, the two forms of grey neural network model prove better in terms of prediction accuracy, calculation convenience and robustness. What’s more, they require less to the original data. Thus, the new proposed models are recommended to be applied to different working environment to compensate the thermal error of machine tools. References | Related Articles | Metrics

Select

Robust Tolerance Design Method Based on Cooperative Game 2011, 45 (11):  1587-1591.  Abstract ( 3598 )   Save This paper proposed a robust tolerance design method combining the Nash bargaining analysis in the cooperative game theory and the modeling of robust tolerance design for assembly products. First, the assembly quality and cost considering the robust design request are considered to be the multiobjective optimization objectives. Then a game model is established by identifying the players, the payoff functions and classifying the players’ strategies. Finally, the Nash bargaining method of the cooperative game theory is given. This method is applied to an example of vehicle front structure assembly. The result of the game method compared with the single objective optimization methods shows the feasibility of the procedure in engineering application. References | Related Articles | Metrics

Select

Stepwise CoefficientsModifying Modeling of  Thermal Errors of a CNC Machine Tool 2011, 45 (11):  1592-1596.  Abstract ( 3316 )   Save Based on the analysis of insufficiencies and limitations of the linear regression analysis modeling method, a new modeling method, that is, stepwise coefficients-modifying modeling method (SCMM) whose basic theory and compensation strategies are evolved and elaborated on, was proposed. The modeling and compensation tests were carried out on a CNC turning center. The results show that the fitted errors are nearly close to zero at the sampled data based on that the model was derived (called original sampled data here) while a good conformity with the original sampled data is got at the nonoriginal sampled data, which proves the thermal error model can effectively improve the compensation accuracy. References | Related Articles | Metrics

Select

Simulation and Optimal Design of High-Pressure-Differential and High-Solid-Phase Relief Valves 2011, 45 (11):  1597-1601.  Abstract ( 3648 )   Save Relief valves used in the coal liquefaction equipment are running in an extremely harsh environment with extraordinarily high pressure differential and intensely slurry flow erosion. Based on the finite volume method (FVM), the pressure and flow distributions of relief valves were analyzed, with K-ε turbulence and Mixture multiphase model. Moreover, for the new-style relief valves, variations of pressure drops with valve apertures and turbulence intensities with depths of valve seat hole were studied. Considering the fluid-erosion theory, optimal design was accomplished and the easywearing positions of the relief valves were accurately predicted to provide theoretical basis for the choice of wear resistant materials. The application results show that the easy-wearing positions are coincide with the predictions. Moreover, the working lifetime is largely elongated up to 1 200 hours and suitable for the practical application. References | Related Articles | Metrics

Select

Study of Stray Light Suppression in Fluorescence Detector 2011, 45 (11):  1602-1606.  Abstract ( 3346 )   Save The stray light is one of the most key performances of spectrum instruments, especially when the light signal to be detected is very weak. The main source of stray light in two monochromators of fluorescence detector for high performance liquid chromatography (HPLC) was analyzed. Through the ASAP software modeling, the formation and distribution of stray light in monochromator were simulated, several structures for stray light suppression were presented and designed, including the apertures, vanes and light baffles, then their stray light suppression effects were estimated. When these three structures are installed in the monochromator simultaneously, the stray light suppression ratio can reach up to 80%. The simulation results are verified through experiments, and the experimental results and the simulation results agree well. References | Related Articles | Metrics

Select

Modeling and Implementation of Hydraulic Motor with Digital Distribution and Speed Adjusting Mechanism 2011, 45 (11):  1607-1612.  Abstract ( 3504 )   Save  A new type of hydraulic motor with digital distributor on which ten high speed solenoid on/off valves are mounted was investigated. The operating principle and the structure characteristics are introduced. The mathematical model of this hydraulic motor is established and the simulation about speed adjusting and direction change characteristics is conducted. The simulation results show that the new digital distributor can not only realize the speed adjusting  by varying the duty cycle of the control signal but also change the rotary direction of the new hydraulic motor by switching the distribution tables. Finally, the model machine of this new type of hydraulic motor was developed and experiments were carried out to validate the simulation results. The experimental results show that the model of the new hydraulic motor is correct and effective. References | Related Articles | Metrics

Select

A Three-dimensional Model on Rotating Stall in Unparallel Wall Vaneless Diffusers 2011, 45 (11):  1613-1618.  Abstract ( 3239 )   Save A 3D model wass presented to study the occurrence of weak rotating waves in unparallel wall vaneless diffusers in centrifugal compressors. The undisturbed flow was first calculated by strongly implicit procedure (SIP), and the discrete linearlised 3D compressible Euler equations were then solved employing singular value decomposition (SVD) technique. The critical inlet mass flow rate for rotating stall and the relative rotating wave speed were predicted. Three different shapes of shroud wall: convergent, convergent and divergent, and constant area tapered shroud walls were studied. The results show the suppression effects on rotating stall of diffusers with contracting shaped shroud walls, especially of long diffusers. The critical mass flow rate also varies with inlet Mach number and diffuser outlet/inlet radius ratio. The results from the model developed agree qualitatively well with those in open literatures. References | Related Articles | Metrics

Engineering Mechanics

Select

Effect of ViscosityTemperature Characteristics on the Behavior of Hydro-Viscous Drive 2011, 45 (11):  1619-1625.  Abstract ( 2923 )   Save The object of this work is to investigate the effect of temperature rise resulting from rotary speed difference between driving and driven plates on the performance of hydroviscous drive. A simplified mathematic model of the steady and laminar flow between two flat plates was established with consideration of viscositytemperature characteristics. The numerical solution of temperature, shearing stress and viscous torque were obtained by using computational fluid dynamics (CFD) code FLUENT. Then, an experiment rig was designed and developed for this work. The numerical and experimental results show that the relationship between output viscous torque and output rotary speed is nonlinear because of viscositytemperature characteristics. It also indicates that viscous torque increases as input flow rate increases, and the magnitude of viscous torque increment is significant when the output rotary speed is low. This research provides a theoretical foundation for the optimization of the performance of hydroviscous drive. Key words： References | Related Articles | Metrics

Mechanical Engineering

Select

Investigation of Sphere Grinding Process Control on the Basis of Neural Network 2011, 45 (11):  1626-1631.  Abstract ( 3264 )   Save A precision sphere grinding system was introduced. On the basis of mechanism of sphere grinding system and grinder structure, the cause of sphere form error was analyzed. BP neural network was used to fit the nonlinear relationship between feed rate, grinding section and spindle current. And  the current was kept stable by adjusting feed rate previously at different grinding section, therefore, constant power grinding was obtained. References | Related Articles | Metrics

Select

Application of Kernel Principal Component Analysis Based on Geodesic Distance in Pattern Recognition of Gear Pump 2011, 45 (11):  1632-1636.  Abstract ( 4325 )   Save As traditional Gauss radial basis kernel which adopts the method of calculating Euclidean distances can not describe completely the relationship between the nonlinear vibration sample data, an improved kernel principal component analytic method was proposed. The method substitutes geodesic distance for Euclidean distance in Gauss radial basis kernel, establishes an appraisement function based on scatter of the sort and space between different sorts, and then uses genetic algorithm (GA) to optimize the k parameter within geodesic distance and delta parameter within Gauss radial basis kernel. The gear pump vibration output signals are decomposed into a number of intrinsic mode function (IMF) components and a residue component, and the method calculates ten nondimensional parameters of each IMF and residue component, then using the optimized kernel function to analyze original parameters. The condition recognition result of gear pump vibration signals in different conditions shows that the novel method is effective. References | Related Articles | Metrics

Metallography and Metallurgical Technology

Select

Robust Design Method for the Seizure Problem of Hydraulic Slide Valve 2011, 45 (11):  1637-1642.  Abstract ( 3287 )   Save For the purpose of solving seizure problem of hydraulic slide valve caused by viscous heating, a robustness design method was put forward basing on the methods of airflow-coal-heat coupled of the hydraulic slide valve structure and multidisciplinary design optimization. Using ordered coupling style, under the airflow-coal-heat coupled of the hydraulic slide valve structure, sensitive factors of seizure of hydraulic slide valve caused by the spool deformation are obtained by the flow finite element method. And, the response relation between the spool deformation and sensitive factors is expressed by the response surface function model.Then, the spool structure of the hydraulic slide valve is designed by the 6σ design method and the robustness of the designed spool is verified by Monte Carlo method.The example shows the spool structure,placket of slide valve, the load flow rate,the media temperature are the sensitive factors that give rise to the seizure of hydraulic slide valve. Robust design method is better than traditional design methods for the seizure of slide valve and multi-factor complex problems. References | Related Articles | Metrics

Mechanical Engineering

Select

Fault Diagnosis with Bayes of Sequential Discrete Event Mechatronic Systems Based on Petri Net 2011, 45 (11):  1642-1646.  Abstract ( 3254 )   Save This paper presented a novel method for fault diagnosis of a proposed sequential discrete event mechatronic (SDEM) system based on Petri net. A timed series connection of sequential discrete event Petri net was defined to model the SDEM system. Time measurement of transition was considered as a statistic. A Bayes based test certification method was put forward and applied in the significant test of variance difference. The prior knowledge was well combined with the real time monitoring information based on the proposed method. It was used in fault diagnosis of an automatic material transfer system and the results illustrate the validity and the feasibility of the method. References | Related Articles | Metrics

Metallography and Metallurgical Technology

Select

Study on Sphere Grinding Temperature of Coated Workpiece with Block Structure Cup Wheel 2011, 45 (11):  1647-1652.  Abstract ( 3387 )   Save The triangular heat source model and the effective width of moving heat source were used to deduct theoretical formula of temperature field according to the real conditions of the sphere grinding of coated workpiece with block structure cup wheel. The dynamic effect of grinding toward heat transfer process, the face temperature of wear debris and the onedimension heat transfer model were integrated to study on ratio of heat introduced to workpiece. The grinding temperature and surface morphology were compared between the block structure cup wheel and normal cup wheel by the experiment, and the influence of grinding parameters toward grinding temperature was also analyzed. The results show that there are lower grinding temperature and better grinding conditions in sphere grinding of coated workpiece with block structure cup wheel than in that with normal cup wheel. References | Related Articles | Metrics

Select

Study on Limit Formability of 1 000 MPa Dual Phase Steel 2011, 45 (11):  1653-1656.  Abstract ( 2935 )   Save Through the cup drawing test, the onset crack and limiting drawing ratio (LDR) of 1 000 MPa dual phase (DP) steel were identified. Three yielding models: Hill, Barlat and BBC were compared in the numerical simulation. The results show that LDR of 1 000 MPa DP steel is 2.07. And Barlat yield criterion is suitable for actual test. Unlike traditional sheet materials whose crack has obvious necking, the crack mode of 1 000 MPa DP is a tensile shear fracture and cracks are on alternating 45° planes, through thickness. References | Related Articles | Metrics

Select

Identification of Johnson-Cook Constitutive Model by Finite Element Analysis 2011, 45 (11):  1657-1660.  Abstract ( 5474 )   Save An inverse approach was applied to identify the material parameters of Johnson-Cook constitutive equation which is largely used for describing materials’ behaviour in previous conditions. The shear experiments over a wide range of temperatures (20-1 000 °C) and strain rates (1-5 000 s-1) and the finite element method simulations were carried out for martensitic stainless steel 410. The goal of the inverse method is to find a parameter array which minimizes the difference between the experimental and numerical forcedisplacement data. The initial parameters are optimized by nonlinear leastsquare method. It is observed that the parameters optimized generally represent well the flow behaviours of material except the damage domain. References | Related Articles | Metrics

Select

Experimental Study on the QuasiStatic Axial Crush Response of High Strength Steel ClosedHat Structures 2011, 45 (11):  1661-1667.  Abstract ( 3027 )   Save In order to study the influence of forming history on the crash behavior of auto-body component, axial crush behavior and energy-absorption performance were compared on the spot-welded closed-hat structures fabricated with different forming conditions for two high strength steels, HSLA340 and DP590 respectively. It was proved that the local material strengthening and geometry weakening resulted from the stamping process significantly affect the post-buckling mode of the hat structures subject to axial loading condition. As a result, the energy absorption of stamped components is lower than that of bent component. In addition, the sheet metal tearing is observed on the crushed components formed under high blank-holder-force stamping condition, which is believed to be dependent on both the strain history and stress state. Due to the special character of low yield/ultimate strength ratio of DP590, the energyabsorption performance of DP590 components is always superior to that of HSLA340 components. References | Related Articles | Metrics

Select

Microbending Moment of Brass Foils Based on Strain Gradient Hardening Model 2011, 45 (11):  1668-1672.  Abstract ( 3215 )   Save The microbending experiments of brass were investigated and there exist the obvious size effects that bending moment increases with foil thickness decreasing. The microbending moments are predicted by classical plastic theory and different strain gradient theories, which shows that the predicted results based on the modified NixGao model are very close to the experimental data and the equation of material intrinsic length is reasonable. The material intrinsic length is the function of shear modulus, initial yield strength, Burger’s vector and twins layers across the foil thickness. References | Related Articles | Metrics

Select

Multi-Objective optimization of Forming Process for Auto-body Panel Based on Springback Control 2011, 45 (11):  1673-1677.  Abstract ( 3651 )   Save Selection criteria of objective function in the optimization model aimed to reduce springback for auto-body panel were discussed. Taking the automobile roof panel as an example, a multi-objective optimization model was established to control springback. The design of experiment (DOE),radial basis function neural networks  (RBF) and non-dominated sorting genetic algorithm (NSGA-II) were  employed to solve the model. The solution was compared with that of the corresponding singleobjective optimization models to analyze the influence of forming process on springback. The results show that blankholder force influences the amount of plastic deformation significantly, and thus the amount of springback. large plastic deformation would occur and springback would decrease rapidly with increasing blankholder force, but when it increases to a certain extent springback would also increase slightly, while drawbead forces have great effect on the internal stress distribution of the sheet metal, thus eventually influence trimming springback. Compared with corresponding single-objective optimization models, the proposed multi-objective optimization model considers forming defects more comprehensively and is more reasonable for application. References | Related Articles | Metrics

Select

The Research of the Anisotropic Fatigue Behavior of 7475 Aluminum Alloy Plate 2011, 45 (11):  1678-1683.  Abstract ( 4013 )   Save The anisotropic fatigue behavior of aircraft aluminum alloy plate was investigated by using bending fatigue test. The results show that after the rolling process, Al7475-T3 forms a pancake structure and the resistance to fatigue damage has been improved. The specimens taken from the 3 plans (S-T,S-L,T-L) show the highest fatigue strength reaches 200 MPa in the room temperature bending fatigue test, except the performance of plan T-L is isotropic, the other two plans S-T and S-L both show us anisotropic. Based on the weakest link theory, using the probabilistic fatigue criterion, the simulation of the anisotropic fatigue is applied to analyze the possibility of the nucleation of microcracks in the aluminum plate, but the result of the simulation is far from that of the actual situation. Taking into consideration of both the effective slip length of grains and the size of inclusions which affect the fatigue strength in the model, the Kitagawa curve is in good agreement with the actual situation. References | Related Articles | Metrics

Select

Research on Pulse Generator and Pulse Control Technology for Micro Electrical Discharge Machining 2011, 45 (11):  1684-1689.  Abstract ( 3456 )   Save Aiming at improving the efficiency of micro electrical discharge machining (EDM), the characteristics of micro-EDM was analyzed, the main discharge circuit was improved, and a pulse generator for micro-EDM based on FPGA was developed. The function of gap status detection is integrated that every single pulse can be detected and the harmful discharge pulse can be cut off in time. A sweep pulse circuit was designed. The debris can be evacuated out of the discharge gap by the exploding effect of the sweep pulses, and the gap status can be improved. With this pulse generator, a preferable result is achieved in the experiment of machining of a deep micro-hole on a CNC controlled desktop micro-EDM machine. References | Related Articles | Metrics

Select

Spherical Shape Error Analysis and Compensation in Hard Sphere Grinding 2011, 45 (11):  1690-1694.  Abstract ( 3341 )   Save  In order to improve the precision of the spherical shape of hard sphere after grinding, the source of the spherical shape error in a novel hard sphere grinding machine tool was analyzed. The backup sphere grinding was proposed for the spherical shape like saddle which appears more frequently in practice. The experimental results indicate that the backup sphere grinding can decrease the spherical shape error effectively. It can benefit the hard sphere grinding greatly.   References | Related Articles | Metrics

Select

Experimental Study of Shear Fracture on Advanced High Strength Dual-Phase Steels 2011, 45 (11):  1695-1699.  Abstract ( 3445 )   Save Fracture characteristics of advanced high strength DP(dual-phase) sheets in stretch-bending over a tight die radius were investigated through flanging and groove-shape dies. Flanging result shows the higher the strength grade of DP sheet is, the more chance shear fracture occurs. The groove-shape tests and simulations suggest the shear fracture around the tight radius only occurs under high BHF, and necking on the wall happens when BHF is low. The eventual failure mode during sheet metal forming operations of AHSS is viewed as the competition between necking and shear fracture, whichever criterion is satisfied first. References | Related Articles | Metrics

Select

Optimization Analysis of Welding Reverse Deformation for the Side Beam of Bogie Frame 2011, 45 (11):  1700-1704.  Abstract ( 4218 )   Save Based on the thermal-elastic-plastic theory, the welding residual deformation’s numerical simulation was done with APDL and the field tracking measurement was also made with the side beam. It was concluded that the computation result  is basically consistent with the measured data and the error is within 6%. On the basis of the numerical simulation model, and combined with the scheme of reverse deformation, multi-layer optimizing computer was utilized, the optimization analysis of the reverse deformation was done with numerical simulation model, the optimum scheme was obtained. Compared with the welding without reverse deformation, the optimum scheme can make bend deformation reduce about 65%. The optimum scheme provides reliable theoretical references for controlling welding residual deformation and selecting the welding technology and determining deformation reserved. References | Related Articles | Metrics

Select

Numerical Simulation and Experiments on High Hardness Coating Grinding Temperature Field 2011, 45 (11):  1705-1709.  Abstract ( 3884 )   Save Through both of numerical simulation and experimental study, the grinding temperature field of WC-Co high hardness coating was analyzed. Based on the moving heat source theory, combining with the grinding conditions and the property of the workpiece, the temperature field model of diamond cup wheel grinding of WC-Co coating material was established and simplified through appropriate assumption. FEM (Finite Element Method) based numerical simulation of WC-Co coating grinding temperature field was then performed. A novel coating grinding temperature measurement method was proposed to experimentally research the grinding temperature. A good agreement has been achieved between the simulation and experiment, which shows the proposed methodologies can be effectively applied to analyze the coating grinding temperature and provide a means for research on the high hardness coating grinding mechanism. References | Related Articles | Metrics

Select

The Influence Factors of Forming Results in Medium-Thick Sheet Metal High Boss Forming Process 2011, 45 (11):  1710-1714.  Abstract ( 2867 )   Save Three kinds of defects which affect the boss height during the forming process were analyzed. Based on the analysis, the concept of effective volume rate was put forward as index. The orthogonal experimental analysis on the influencing factors of forming result was carried out with the use of numerical simulation and physical experiment to find out the key influence factors. A further study was made to find how the key factors influence the high boss forming results. The research results provide guidelines for the process design and die structure optimization. References | Related Articles | Metrics

Select

Analysis and Motion Planning for Multiaxis Machining Process Based on Hierarchical Model 2011, 45 (11):  1715-1719.  Abstract ( 3073 )   Save Abstract： For complex surface multi-axis machining process, a complete hierarchical model for multiaxis milling was presented. The geometric model, kinematics model and mechanistic model are integrated to analyse the machining methods. The method selected for geometric stock modeling is the dexel approach. The cutter workpiece engagement defines the instantaneous intersection boundary between the cutting tool and the in-process workpiece. From the CWE, the cutter entry-exit angles and depth of cuts are found and used to calculate the instantaneous cutting forces. The kinematics model also supports the calculation of workpiece updating and cutting force during the multiaxis milling process. The constrained optimization is solved by sequential quadratic programming and the machine operates at threshold levels. The production time in a flank milling propeller was reduced considerably to 20% with the satisfaction of precision demand. Key words： References | Related Articles | Metrics

Automation Technique, Computer Technology

Select

Extension Surface Reparation in Checking Fixture Design 2011, 45 (11):  1720-1724.  Abstract ( 3186 )   Save Checking mechanism design, one of the most complex tasks in the checking fixture design (CFD), for which accurately mate to the surface shape of the checked part, usually contains lots of complicated surface extension operations. However, there are many branching and intersection/overlapping problems at the first-order-discontinuity points of B-rep edges by current surface extension methods. A new automatic surface extension approach was proposed, which can repair the branching and intersection/overlapping problems at the first-order-discontinuity points. By recognizing edges of checking surfaces without manual intervention, it judges the first-order-continuity condition at the co-endpoint, if the endpoint satisfies the convex condition, it will use spherical positive weights rational quartic Bézier curve to bridge the branching offset curves, and if the endpoint satisfies the concave one, it will use cubic Bézier curve to bridge the gap after cutting the intersection/overlapping curves. A car fender CFD as an example illustrates its feasibility and practicability. References | Related Articles | Metrics

Communication and Transportation

Select

A Three-Dimensional Compressible Flow Model on Vaneless Diffuser Stall 2011, 45 (11):  1725-1730.  Abstract ( 3992 )   Save A three-dimensional compressible flow model was presented to study the occurrence of rotating waves in vaneless diffusers of centrifugal compressors. Solutions to the discrete 3D Euler equations for compressible flow were obtained via singular value decomposition (SVD) method. Critical inlet mass flow rate of vaneless diffuser stall and relative rotating speed of stall cell were calculated. The effects of inlet Mach number were studied and the results show that both critical inlet mass flow rate and rotating wave speed vary with inlet Mach number especially when the diffuser is long. In addition, critical inlet mass flow rate and rotating wave speed are also influenced by diffuser outlet/inlet radius ratio, departure from axial uniform distribution of the undisturbed radial velocity at the diffuser inlet, and impeller back swept angle. Finally, a comparison with experimental results in open literature was made, and the results of 3D model show better agreement than those of 2D model. References | Related Articles | Metrics

Automation Technique, Computer Technology

Select

PDMS-Based Neural Microelectrode Arrays for Retinal Prosthesis 2011, 45 (11):  1731-1736.  Abstract ( 3308 )   Save In order to improve the contact between electrode sites and target neurons by using conformable substrates, and meanwhile ensure the reliability of the microelectrode arrays, a new method for fabricating crack-free polydimethylsiloxane (PDMS)-based microelectrode arrays (MEAs) was presented. The device is constructed by depositing, patterning and electroplating gold to form wires and electrode sites on silicon wafer, and then embedding the wires in PDMS, exposing the electrode sites and bonding the second PDMS layer for bottom insulation. The embedding and exposing process involves pouring PDMS on the electroplated metal microstructures, curing with clamping and wet etching PDMS residues. In this way reliable and robust conformable MEAs were achieved. Prototype MEAs were also tested and evaluated by SEM and impedance test. The experimental results show, compared with conventional PDMS-based MEAs, the electrochemical impedance decreases by 60%. The PDMS-based MEAs fabricated by the method proposed in this paper exhibite obvious advantages in mechanical and electrical properties. References | Related Articles | Metrics