MEMS 기술로 제작된 가스 센서 어레이를 이용한 유해가스 분류를 위한 간단한 통계적 패턴인식방법의 구현

In this paper, rectification methods for micro-energy harvesting systems are proposed and estimated. We present introduce two methods. The first is a mechanical rectification. The second is semiconducting rectification which is fabricated through MEMS technology. Vibration-driven micro-energy harvesting by micro electro mechanical systems (MEMS) technology is needed because the electrical power consumption of our society is increasing. But most of the vibration-driven generators supply alternating-current and intermittent electro energy. For using, it is necessary to construct the micro energy system supplying direct current. Therefore, we present the micro energy system that is composed of vibration-driven micro-energy harvesting, rectification and energy storage. In particular, we consider the rectification in this paper. In designing, we consider that vibration-driven micro-energy harvestings are developed through MEMS technology. Compatibility between semiconductor process and MEMS process is hard to achieve in materials, temperature, contamination and so on.

The water condensation is important for wide range of industrial systems such as condensers and heat exchangers of steam power plants and refrigerators. The condensation generally has two patterns; filmwise condensation (FWC) and drop-wise condensation (DWC). DWC has one-tenth higher heat transfer coefficient than that of FWC. It has been pointed out by many investigators that DWC occurs on the hydrophobic surface and FWC occurs on hydrophilic surface. However, the durability of those hydrophobic effects was not clear enough. In order to maintain a sufficiently long DWC, it is important to understand the effect of the surface property and structure on the condensation surface in more detail. The recent advancement of MEMS (Micro Electro Mechanical System) technology enables us to change the physical nature the surface in the micro scale. It is expected that the hydrophobic surface by the MEMS technology may kept DWC for a longer time. In the present paper, we experimentally investigate the effects of thin metal film and micro structured surface on condensation pattern. Especially, our condensation experiments were performed with the micro structured surfaces by using etching and the metal thin film surfaces by sputtering for approximately 24 hours. Silicon (Si) wafer was used as a basic surface. For the metal thin films surface, we used sputtered Lead (Pb) and Titanium (Ti) on Si surface. For the micro structured surfaces, micro-structured grid was etched on Si surface with several conditions. In order to obtain the relation between the condensation pattern and surface condition, the surface conditions were measured by laser micro-scope, contact angle meter and atomic force microscope (AFM). For the metal thin films surface, condensation patterns on thin Pb film surface showed DWC. Meanwhile, condensation patterns on thin Ti surfaces showed FWC. From our results, the adsorption forces decreased with increasing contact angle on DWC for Pb. On the other hand, the adsorption forces increased with decreasing contact angle on FWC for Ti. For the micro structured surfaces, condensation pattern was FWC and contact angle decreased in our experimental results. This is because that the condensed water is accumulated in the groove on the micro structure surface.

Design, development, fabrication and evaluation of the dynamics of a graphene based underwater acoustic vector sensor: A simulation and experimental study

A multi-try counter-meshing gears stronglink based on micro electromechanical system (MEMS) technology is introduced, including research, design, couple and fabrication of unique signal (UQS) for some specified fields of information security. The stronglink consists of two groups of metal counter-meshing gears, two pawl/ratchet mechanisms, two driving micromotors and two resetting micromotors. The resetting micromotors make counter-meshing gears withdraw by raising pawls so that the interfered counter-meshing gears will be relieved. The energy-coupling element is a photoelectric sensor with a circular notched plate. The counter-meshing mechanism is fabricated using the ultraviolet-lithographie, galvanoformung and abformung (UV-LiGA) process and a precision mechanical technique. The stronglink can be tried several times if the correct resetting code is known.

All spacecraft rely on radiative surfaces to dissipate waste heat. These radiators have special coatings that are intended to optimize performance under the expected heat load and thermal sink environment. Typically, such radiators will have a low absorptivity and a high infrared-red emissivity. Given the dynamics of the heat loads and thermal environment it is often a challenge to properly size the radiator. In addition, for the same reasons, it is often necessary to have some means of regulating the heat rejection rate of the radiators in order to achieve proper thermal balance. The concept of using a specialized thermal control coating which can passively or actively adjust its emissivity in response to such load/environmental sink variations is a very attractive solution to these design concerns. Such a system would allow intelligent control of the rate of heat loss from a radiator. Variable emissivity coatings offer an exciting alternative that is uniquely suitable for micro and nano spacecraft applications. This permits adaptive or “smart” thermal control of spacecraft by varying effective emissivity of surfaces in response to either a passive actuator (e.g., a bi-metallic device) or through active control from a small bias voltage signal. In essence the variable emittance surface would be an “electronic louver.” It appears possible to develop such “electronic louvers” through at least three different types of technologies: Micro Electro-Mechanical Systems (MEMS) technology, Electrochromic technology and Electrophoretic technology. This paper will concentrate on the first approach using both MEMS and Micromachining technology to demonstrate variable emissivity.

MEMS (Micro Electro Mechanical Systems) technology is becoming a crucial enabling technology for optical and RF telecommunication applications due to the performance, cost and integration advantages. All-optical switches and silicon optical benches for optical network systems and RF MEMS components such as RF MEMS switches, tunable capacitors, high Q inductors, and thin film bulk acoustic resonators for miniaturized single chip RF transceivers are discussed. Despite all the promising aspects, practical problems to be addressed for successful commercialization are not trivial. By reviewing optical and RF MEMS research activities and some of the implementation examples, key success factors of MEMS components for the commercialization are discussed.

RF MEMS (radio frequency micro electro mechanical systems) technology holds great promise for wireless communication and sensor systems. Excellent MEMS switching devices have recently been developed, but because of packaging problems, no commercial integrated product exists. The objective of the ongoing work at CFD Research Corporation (CFDRC) and Morgan Research Corporation (MORGAN) is to develop novel packaging concepts, design tools, and demonstrated RF MEMS packaged devices for high frequency applications.

Evaluation of a multiple gas mixture with a simple MOSFET gas sensor array and pattern recognition

Chemical warfare agent sensor using MEMS structure and thick film fabrication method

Micro electro mechanical systems (MEMS) technology has developed considerably in recent years and many sensors utilizing this technology are available in the market. MEMS technology enables miniaturization, mass production, and cost reduction of many sensors. In particular, MEMS inertial sensors that include an acceleration sensor and an angular velocity sensor (gyroscope, or simply ldquogyrordquo) are the most popular devices. Applications of inertial sensors have now extended into the field of networked sensing systems. In this presentation, we will describe current MEMS inertial sensors and their applications.

Precision guided munitions (PGMs) are critical to the Maneuver Battalion Commander's success on future rapidly deployed battlefields. These PGMs will provide an increase in lethality, significantly improve survivability, reduce collateral damage, minimize non-combatant casualties, and decrease the logistics burden or increase the number of kills from the standard logistics load. PGMs all require inertial measurement sensors embodied in an IMU. Until now, they have been large, expensive, and could not readily survive the high G launch environments. MEMS technology provides inherent cost savings and size reduction and is ideal for application to navigation and control systems for small missiles and munitions. Using MEMS technology, gyroscopes, accelerometers and control electronics can readily be integrated to form a tightly packaged, low-cost, extremely small, high performance IMU suitable for munition, missile, and personnel guidance as well as other applications. This paper describes the current Army development underway and its partnership with industry to achieve the necessary requirements. The program goal is to survive a 20,000 g gun launch and meet a 1/spl deg//hr, 1/2 milli-g performance capability. The MEMS IMUs will significantly reduce the cost of precision-delivered missiles and munitions, as well as expand precision delivery capability to artillery ammunitions, and thus reduce the number of required rounds by more than 30% while meeting roughly 90% of the tactical weapons fleet navigational requirements.

MEMS (micro electro mechanical systems) technology could be applied on bio-chips to measure and detect micro objects. Generally, the detected signal is so small that we need to amplify it for next processing (such as A/D converter). In this study, we develop a trans-impedance amplifier (TIA) circuit to detect the blocking conductance when particles across an ion-pore. Consider the simple circuits, simple manufacture process, and the capability of integrating with MEMS process. The TIA circuit and the MEMS ion-pore is designed based on 0.35mum CMOS process. The measured results of this amplifier are 94dBOmega high gain, low noise as the M.D.S. of 25nA, and the bandwidth larger than 15MHz

Micro electro mechanical systems (MEMS) have experienced an explosive growth over the past few years driven mainly by its physical properties and its promising technological applications in many different fields, particularly in space and Radio Frequency (RF) systems. MEMS technology exhibits greater advantages over the existing semiconductor switches. In this paper, electro-thermal performances of a two hot arms actuator MEMS switch have been investigated. The switch is designed using CST Microwave Studio. Some mathematical equations have been developed to see the temperature distribution of the hot arms as voltage applied on it. Based on this thermal distribution, the linear thermal expansion of the hot arms and the air gap used in this switch is expressed mathematically. The developed equations have been solved and analyzed using the MATLAB software. This analysis shows that this MEMS switch has a wider range of linear operation and has extremely higher breakdown voltage.

Development of wireless vibration sensor using MEMS for tunnel construction and maintenance

A new sacrificial layer technology for the fabrication of silicon carbide (SiC) based micro electro mechanical systems (MEMS) is described using silicon germanium (SiGe) as sacrificial material. An extremely high etch selectivity between SiC and SiGe of up to 1:1000000 was achieved when using chlorine trifluoride (ClF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) as etchant in a dry plasmaless etch process. This enormous selectivity enables the fabrication of free standing SiC microstructures like combs or membranes with a strongly reduced need for perforation patterns, which are typical for silicon dioxide sacrificial layers etched selectively to silicon by hydrofluoric acid (HF) in liquid or vapour phase. Only few and small openings are necessary to fully release large SiC structures with the sacrificial layer technology presented, therefore allowing higher degrees of design freedom for MEMS compared to traditional release technologies.