基于MEMS技术FDM 3D打印机自适应调平系统

针对熔融沉积成型(FDM)3D打印机在使用过程中出现的打印模型粘接不牢、翘曲变形和抽丝等问题,基于微电机系统(MEMS)技术设计了一种4点式自适应调平系统。该系统利用MEMS双轴倾角传感器测量打印平台的倾角以确定位于最高点的调节点,运用调平算法计算其它3个调节点的举升高度调节量,使用机电式调平机构采用逐高式调平方法实现打印平台的水平调节。研究表明,该系统具有原理简单,调平时间短,可靠性高等特点,能够满足3D打印机调平的性能指标要求,还可推广应用于其它各类调平系统。

微机械技术与微传感器发展——21 世纪航天传感器技术展望

论述了微机械技术对传感器发展的巨大推动作用及其在航天传感器上的应用前景，并介绍了微机械技术在传感器上近期应用研究的主要内容。

世界微电机市场纵览

一、世界微电机发展现状 随着工业自动化、办公自动化和家庭自动化的不断发展以及计算机、通信、汽车、家电、玩具产量的不断提高,世界微电机的市场容量正以年增6％以上的较快速度向前推进。日本是世界微电机的最大制造国,1996年其产量达23亿台,出口量达16亿台,2000年其产量降至17亿台,产值也下降至673.3亿日元,约为10年前日本微电机产值的一半。日本Mabuchi马达公司是全球最大的微电机制造商,它制造了世界DC电机市场产品一半以上,在我国大陆和台湾省、马来西亚、越南等地均设有生产厂,该公司在全球各地的DC电机综合生产能力已达15亿台。由于日本在磁性材料、电子控制和生产工艺上的领先地位,从而使其不仅在微电机的生产方面居世界霸主地位,在技术领域也雄居世界前沿,其微电机产品具有大转矩、小尺寸、高控制精度、低功耗、长寿命和低成本的竞争优势。

Preparation and Electrochemical Characteristics of Three-dimensional Manganese Oxide Micro-supercapacitor Electrode

In order to increase the electrode surface area and enhance the charge storage capacity, we study the micro electro mechanical system technology to fabricate three-dimensional high aspect ratio micro-electrode structure based on glass. The anodic constant potential method is employed to deposit manganese oxide as electroactive substances on the micro-electrode surface. Cyclic voltammetry and constant current charge-discharge method are both used to prepare electrode electrochemical performance testing, with a two-dimensional electrode without structure for comparison. Experimental results show that three-dimensional elec- trode structure can effectively enhance the charge storage capacity. At 1.0 mA/cm2 charge- discharge density, the three-dimensional electrode shows a capacitance of 17.88 mF/cm2, seven times higher than the two-dimensional electrode.

MEMS Test System Based on Virtual Instrument Technology

On account of the multiformity of MEMS devices, it is necessary to integrate with some optical measurement techniques for meeting static and dynamic unit test requirements. In this paper, an automated MEMS test system is built of some commercially available components and instruments based on virtual instrument technology. The system is integrated with stroboscopic imaging, computer micro-vision, microscopic Mirau phase shifting interferometry, and laser Doppler vibrometer, and is used for the measurement of full-view in-plane and out-of-plane geometric parameters and periodical motions and single spot out-of-plane transient motion. The system configuration and measurement methods are analyzed, and some applications of the measurement of in-plane and out-of-plane dimensions and motions were described. The measurement accuracy of in-plane dimensions and out-of-plane dimensional is better than 0.2 um and 5 nm respectively. The resolution of measuring in-plane and out-of-plane motions is better than 15 nm and 2 nm respectively.

Real-Time, Automatic and Wireless Bridge Monitoring System Based on MEMS Technology

Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is sometimes unreliable or even wrong in the case of careless operation. The inspection activity itself is dangerous for inspectors, e.g., bridges are located in the sea or river. Some semi-automatic monitoring methods are recently employed, but they are either very expensive or do not work properly. Therefore, the traditional bridge monitoring process becomes an increasing challenge for bridge operators. In this paper, a real-time and automatic bridge monitoring system is presented to meet the bridge monitoring needs, and MEMS （Micro Electro Mechanical Systems） are the key building block in this system. By using the MEMS-based sensors, it is much more efficient and accurate in monitoring bridges with the measurement of inclination, acceleration, displacement, moisture, temperature, stress and other data.

Design and Performance Analysis of Micro Proton Exchange Membrane Fuel Cells

This study describes a novel micro proton exchange membrane fuel cell(PEMFC)(active area,2.5 cm2).The flow field plate is manufactured by applying micro-electromechanical systems(MEMS) technology to silicon substrates to etch flow channels without a gold-coating.Therefore,this investigation used MEMS technology for fabrication of a flow field plate and presents a novel fabrication procedure.Various operating parameters,such as fuel temperature and fuel stoichiometric flow rate,are tested to optimize micro PEMFC performance.A single micro PEMFC using MEMS technology reveals the ideal performance of the proposed fuel cell.The optimal power density approaches 232.75 mW·cm-1 when the fuel cell is operated at ambient condition with humidified,heated fuel.

Preparation of PVC/PVP composite polymer membranes via phase inversion process for water treatment purposes

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.

Research and Review on the Development of Mechanical and Electrical Integration of System Function Principle and Related Technologies

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.

Silicon Deep Etching Techniques for MEMS Devices

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.

A planar parallel manipulator based novel MEMS device bonding system

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.

Design and Analysis of Self-excited Miniature Magnetic Generator

Nowadays, electronic devices are more and more integrated into everyday life. These seamless integrations focus on mobility, but at the same time strive to be unobtrusive to the end user. With the introduction of personal data assistants and intelligent cellular phones for the searching of the website, true mobile computing is closer than ever. However, battery technology, which powers most of these mobile connectivity solutions, has not kept up the same pace of improvement. The paper describes a methodology for the design and performance of a self-excited permanent-magnet generator applied to low power supplies. It combines an analytical field model, a lumped reluctance equivalent magnetic circuit, and an equivalent electrical circuit. An illustrated example of a 15-mW, 290-r/min generator is given, and the analysis techniques are validated by measurements on a prototype system.

Applications of MEMS devices in nanosatellite

micro-electro-mechanical system （MEMS） device has the advantages of both electronic system and mechanical system. With the development of MEMS devices for satellite, it is possible to establish much lighter and smaller nanosatellites with higher performance and longer lifecyele. The power consumption of MEMS devices is usually much lower than that of traditional devices, which will greatly reduce the consumption of power. For its small size and simple architecture, MEMS devices can be easily integrated together and achieve redundancy. Launched on April 18, 2004, NS - 1 is a nanosatellite for science exploration and MEMS devices test. A mass of science data and images were acquired during its running. NS - 1 weights less than 25 kg. It consists of several MEMS devices, including one miniature inertial measurement unit（MIMU） , three micro complementary metal oxide semiconductor （CMOS）cameras, one sun sensor, three momentum wheels, and one micro magnetic sensor. By applying micro components based on MEMS technology, NS - 1 has made success in the experiments of integrative design, manufacture, and MEMS devices integration. In this paper, some MEMS devices for nanosatellite and picosatellite are introduced, which have been tested on NS -1 nanosatellite or on the ground.

A New Approach to Cleave MEMS Devices from Silicon Substrates

Dicing of fabricated MEMS （microelectromechanical system） devices is sometimes a source of challenge, especially when devices are overhanging structures. In this work, a modified cleaving technique is developed to precisely separate fabricated devices from a silicon substrate without requiring a dicing machine. This technique is based on DRIE （deep reactive ion etching） which is regularly used to make cleaving trenches in the substrate during the releasing stage. Other similar techniques require some extra later steps or in some cases a long HF soak. To mask the etching process, a thick photoresist is used. It is shown that by applying different UV （ultraviolate） exposure and developing times for the photoresist, the DRIE process could be controlled to etch specific cleaving trenches with less depth than other patterns on the photoresist. Those cleaving trenches are used to cleave the wafer later, while the whole wafer remains as one piece until the end of the silicon etching despite some features being etched all the way through the wafer at the same time. The other steps of fabricating and releasing the devices are unaffected. The process flow is described in details and some results of applying this technique for cleaving fabricated cantilevers on a silicon substrate are presented.

Experimental investigation on cumulative propagation of thin film buckling under cyclic load

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.