In this work, new composite membranes were successfully prepared via phase inversion technique using polyvinyl chloride(PVC) and polyvinylpyrrolidone(PVP) as polymers and tetrahydrofuran(THF) and N-methyl-2-pyrrolidon...In this work, new composite membranes were successfully prepared via phase inversion technique using polyvinyl chloride(PVC) and polyvinylpyrrolidone(PVP) as polymers and tetrahydrofuran(THF) and N-methyl-2-pyrrolidone(NMP) as solvents. The prepared membranes have been characterized by scanning electron microscope(SEM), and fourier transforms infrared spectroscopy(FTIR). The scanning electron microscope results prove that the prepared membranes are smooth and their pores are distributed throughout the whole surface and bulk body of the membrane without any visible cracks. The stress–strain mechanical test showed an excellent mechanical behavior enhanced by the presence of PVP in the prepared membranes. The membranes performance results showed that the salt rejection reached 98% with a high flux. This, in turn, makes the prepared membranes can be applied for sea and brackish water treatment through membrane distillation technology.展开更多
A novel MEMS device boning system is presented. Aiming at the high velocity, high precision and high flexibility requirements, a novel manipulator of planar parallel structure is developed to substitute ordinary X-Y t...A novel MEMS device boning system is presented. Aiming at the high velocity, high precision and high flexibility requirements, a novel manipulator of planar parallel structure is developed to substitute ordinary X-Y table. In addition, the machine vision is implemented to improve the system＇ s flexibility. The initial angular positions of the joints are estimated by the extended Kalman filter algorithm. As a resuh, the manipulator＇s absolute locating accuracy in its workspace is guaranteed indirectly. For any MEMS device, the bonding system itself can be used as measurement equipment to create the device＇ s geometry model, which is the base to do off-line programming. A quite ideal trade-off between the system＇ s flexibility and efficiency is got. Finally, some verified motion specification of the manipulator, the bonding experimental results and the verified qualities of the bonded devices are provided.展开更多
Silicon deep etching technique is the key fabrication step in the development of MEMS. The mask selectivity and the lateral etching control are the two primary factors that decide the result of deep etching process. T...Silicon deep etching technique is the key fabrication step in the development of MEMS. The mask selectivity and the lateral etching control are the two primary factors that decide the result of deep etching process. These two factors are studied in this paper. The experimental results show that the higher selectivity can be gotten when F - gas is used as etching gas and Al is introduced as mask layer. The lateral etching problems can be solved by adjusting the etching condition, such as increasing the RF power, changing the gas composition and flow volume of etching machine.展开更多
In this paper, we conduct research on the development of mechanical and electrical integration of system function principle and related technologies. Along with the rapid and continuous development of modem science an...In this paper, we conduct research on the development of mechanical and electrical integration of system function principle and related technologies. Along with the rapid and continuous development of modem science and technology, it ＇ s for the penetration and cross of different subjects great push, the more important is caused by technological revolution in the field of engineering and mechanical engineering field under the rapid development of computer technology and microelectronic technology and penetration to the mechanical and electrical integration, which is formed by the mechanical industry lead to trigger a particularly large changes in the mechanical industry management system and mode of production, product and technical structure, composition and function, thus result in industrial production from the previous mechanical electrification progressively electromechanical integration which lead the trend of the current technology.展开更多
As instrument technology is needed for rapid determination of the smaller,thinner and lighter specimens,more stringent demands are related to thin films such as micro-electro-mechanical systems(MEMS),dielectric coatin...As instrument technology is needed for rapid determination of the smaller,thinner and lighter specimens,more stringent demands are related to thin films such as micro-electro-mechanical systems(MEMS),dielectric coatings and electronic packaging.Therefore,the requirement for testing platforms for rapidly determine the mechanical properties of thin films is increasing.Buckling of a film/substrate system could offer a variety of applications,ranging from stretchable electronics to micro-nanoscale metrology.In this paper,a fatigue-loading device has been designed to make the cyclic loading available for investigating the cumulative propagation of thin film buckling.The straight side buckling of thin compressed titanium film with the thickness of 50 nm deposited on organic glass substrates is investigated by using an optical microscope.The cumulative buckling propagation under the cyclic loading of a sequence of peak compression with the frequency 1 Hz is recorded by CCD camera.The buckling extension lengths are calculated by digital image measurement technology.展开更多
文摘In this work, new composite membranes were successfully prepared via phase inversion technique using polyvinyl chloride(PVC) and polyvinylpyrrolidone(PVP) as polymers and tetrahydrofuran(THF) and N-methyl-2-pyrrolidone(NMP) as solvents. The prepared membranes have been characterized by scanning electron microscope(SEM), and fourier transforms infrared spectroscopy(FTIR). The scanning electron microscope results prove that the prepared membranes are smooth and their pores are distributed throughout the whole surface and bulk body of the membrane without any visible cracks. The stress–strain mechanical test showed an excellent mechanical behavior enhanced by the presence of PVP in the prepared membranes. The membranes performance results showed that the salt rejection reached 98% with a high flux. This, in turn, makes the prepared membranes can be applied for sea and brackish water treatment through membrane distillation technology.
基金Supported by the High Technology Research and Development Programme of China （No. 2003AA404060） and the National Natural Science Foundation of China （No.60405008）.
文摘A novel MEMS device boning system is presented. Aiming at the high velocity, high precision and high flexibility requirements, a novel manipulator of planar parallel structure is developed to substitute ordinary X-Y table. In addition, the machine vision is implemented to improve the system＇ s flexibility. The initial angular positions of the joints are estimated by the extended Kalman filter algorithm. As a resuh, the manipulator＇s absolute locating accuracy in its workspace is guaranteed indirectly. For any MEMS device, the bonding system itself can be used as measurement equipment to create the device＇ s geometry model, which is the base to do off-line programming. A quite ideal trade-off between the system＇ s flexibility and efficiency is got. Finally, some verified motion specification of the manipulator, the bonding experimental results and the verified qualities of the bonded devices are provided.
文摘Silicon deep etching technique is the key fabrication step in the development of MEMS. The mask selectivity and the lateral etching control are the two primary factors that decide the result of deep etching process. These two factors are studied in this paper. The experimental results show that the higher selectivity can be gotten when F - gas is used as etching gas and Al is introduced as mask layer. The lateral etching problems can be solved by adjusting the etching condition, such as increasing the RF power, changing the gas composition and flow volume of etching machine.
文摘In this paper, we conduct research on the development of mechanical and electrical integration of system function principle and related technologies. Along with the rapid and continuous development of modem science and technology, it ＇ s for the penetration and cross of different subjects great push, the more important is caused by technological revolution in the field of engineering and mechanical engineering field under the rapid development of computer technology and microelectronic technology and penetration to the mechanical and electrical integration, which is formed by the mechanical industry lead to trigger a particularly large changes in the mechanical industry management system and mode of production, product and technical structure, composition and function, thus result in industrial production from the previous mechanical electrification progressively electromechanical integration which lead the trend of the current technology.
基金supported by the National Natural Science Foundation of China (Grant Nos 10372069, 10732080, 11072174 and 10672120)the Tianjin Natural Science Foundation (Grant No 06YFJZJC00700)
文摘As instrument technology is needed for rapid determination of the smaller,thinner and lighter specimens,more stringent demands are related to thin films such as micro-electro-mechanical systems(MEMS),dielectric coatings and electronic packaging.Therefore,the requirement for testing platforms for rapidly determine the mechanical properties of thin films is increasing.Buckling of a film/substrate system could offer a variety of applications,ranging from stretchable electronics to micro-nanoscale metrology.In this paper,a fatigue-loading device has been designed to make the cyclic loading available for investigating the cumulative propagation of thin film buckling.The straight side buckling of thin compressed titanium film with the thickness of 50 nm deposited on organic glass substrates is investigated by using an optical microscope.The cumulative buckling propagation under the cyclic loading of a sequence of peak compression with the frequency 1 Hz is recorded by CCD camera.The buckling extension lengths are calculated by digital image measurement technology.
