Papers by Keyword: Microsystems

Abstract: The requirements of gears are increasing rapidly in the global market for applications from micro electro mechanical systems (MEMS) to aerospace. Gears of various profiles and types including spiral-conical are used for motion as well as torque transfer in microsystems. The development of such gears is a challenging task because no compromise in their quality is acceptable. It necessitates highly accurate gear manufacturing process. This article presents such a process i.e. wire-assisted electrical discharge machining (WEDM) and development of stainless-steel made spiral-conical gears of miniature size. All minute aspects of spiral-conical gear development by WEDM are reported in this paper. In order to investigate the impact of process parameters and gear quality, an experimental study has been conducted based on Taguchi’s robust design of experiment technique. The developed gears are found with good manufacturing quality characteristics.

Abstract: A new system for converting combustion heat into electric power was proposed on the basis of countercurrent burner with thermoelectric element embedded in a wall separating incoming fresh mixture and combustion products. The wall serves as heat exchanger between combustion products and the fresh mixture. Numerical simulations showed that almost whole combustion heat may be transferred through the thermoelectric element in such system and the total thermal efficiency attained a value close to the conversion efficiency of the thermoelectric device itself.

Abstract: Technology called MEMS (Micro Electro Mechanical Systems) or microsystems are heterogeneous integration on silicon chips and play important roles as sensors. MEMS as switches and resonators fabricated on LSI are needed for future multi-band wireless systems. MEMS for safety systems as event driven tactile sensor network for nursing robot are developed. Wafer level packaging for MEMS and open collaboration to reduce the cost for the development are discussed.

Abstract: Microelectronic substrates like silicon, alumina and LTCC (Low Temperature Cofired Ceramics) allow for high robustness and reliability, 3D packaging (electrical connection, channels, cavities and membranes) as well as integration and application of electronic components whereas piezoceramic materials offer sensor and actuator operations. To combine the advantages of both, integrated solutions are of great interest. This paper deals with two approaches of monolithic integration, (i) screen printing of piezoceramic thick films on microelectronic substrates and subsequent post firing and (ii) integration of pre-fired piezoceramic components into green LTCC multilayer packages and subsequent sintering. Functionality of smart microsystems not only depends on the outer design and construction but to a great part on interaction of substrate and piezoceramic material properties. A thorough choice of materials as well as the understanding and prevention of chemical reactions are necessary to build effective systems.

Abstract: This paper describes novel multi-microchannel, which is the major component of wind velocity and direction sensor based on MEMS technology. The multi-microchannel built in a cylinder, and the channels have been optimized to produce a flow rate that depends on the wind direction according to a cosine function. When two such cylinders placed orthogonally in wind condition, wind speed and direction can be inferred from flow rate data measured from the channels. With the help of Fluent simulation software, this paper not only provides the design ideas of multi-microchannel but also proposes one design approach which meets the practical needs.

Abstract: Lead zirconate titanate (PZT) thick films, a few tens of micrometres thick, are of technological interest for integration with microsystems to create micro electromechanical systems (MEMS) with high sensitivity and power output. This paper examines the challenges faced in integrating thick film PZT with other materials to create functional micro devices. Thermal, chemical and mechanical challenges associated with integration will be examined and potential solutions explored.

Abstract: Intelligent wearable personal systems enabling, e.g. health monitoring, protection & safety and healthy lifestyle, gained strong interest during the last 10-15 years. New generation of body sensors benefit largely from significant technological advances in terms of intelligence, speed, miniaturization, power autonomy and new materials at lower cost. The symbiosis of textiles with wearable computing, augmented reality, human machine interfaces, media and interface design and the collaboration between established electronics and textile industries are leading to a totally new class of large-area, flexible, conformable informative and interactive wearable systems. Further research across disciplines like micro-nano technologies, materials, physiology/biology/medicine and information & communication technologies is necessary in order to achieve highly performing, user-friendly and cost-effective wearable systems. This article presents the state-of-the-art of smart wearable integrated systems for personal applications, outlines current research achievements and discusses trends and challenges for technology, systems and applications.

Abstract: This paper presents two biomedical microsystems for blood cell counting, designed and built through MultiMEMS Multi-Project Wafer (MPW) service and the microBUILDER European project. Dies mm in size, made of a micromachined glass-silicon-glass triple stack, host two new kinds of multiple micro-counters, suitable to investigate the feasibility of blood cell differential analysis by means of Coulter principle in a monolithic lab-on-a-chip, which integrates a microfluidic network, sensing metal electrodes and light-guiding structures. Within these devices, impedance method gains some innovative features, both from microsystem technology itself (low consumptions of chemicals, better analytical performances, low dead volumes in multifunctional interconnected networks, parallel high-throughput processing, low-cost mass production) and from new project solutions: self-aligning illumination allows to use compact external sources (i.e, LEDs) and requires no delicate optics. Different working set-ups (ranging from series with fixed control volume to parallel differential) can be achieved by adding only few external components. It is finally possible to combine electrical and optical measurements, oriented to multi-feature classification of cell sub-populations.

Abstract: This paper presents three kinds of high-temperature test methods for three different materials along with the results. Resistively heated polysilicon film 3.5 micron thick shows ductile behavior at 500°C. Resistively heated nickel 200 microns thick shows decreasing strength at 400°C. Furnace heated silicon carbide 200 microns thick maintains its strength at 1000°C. Strain is measured by laser-based interferometry in the first two cases to obtain complete stress-strain curves, while force-displacement is measured in the third case.