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This paper presents the design and development of a safe MEMS based micro electro-thermal igniter for a safe microfuze for military purpose. The proposed device"s architecture is made of: (1) one pyrotechnical micro igniter, (2) one arming function, (3) one disarming function and (3) one sterilization function. The pyrotechnical electro-thermal igniter consists in a resistive element that converts electrical energy into heat to initiate an energetic material. The arming function permits the igniter to be armed, ready to fire, only if the ignition conditions are respected. For that, a short-circuit to the electrical ground is cut and the igniter is connected to the power supply. The igniter can be reset to the safe mode (disarmed state) thanks to the disarming function that reconnects the igniter's electrical pads to the electrical ground. If necessary the igniter can be sterilized meaning that the system's ignition capability is definitively removed. All these functions are based on the use of two electro-thermal micro switches : one ON-OFF and one OFF-ON. Due to the application requirements (the fuze is used once but after a long storage, all components must have a high level of safety and reliability and the power consumption must be minimized), we opted for a new generation of one shot, safe and reliable micro switches. They are based on electro thermal mechanisms and consist in breaking one electrical connection (ON-OFF switch) or micro soldering locally two electrical connections (OFF-ON switch). Both switches have been developed in MEMS technology, characterized and are presented in this paper. A prototype of safe micro igniter with ON-OFF and OFF-ON switches has been also realized and is presented.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

COTS (Commercial-off-the-shelf) MEMS components are very interesting for space applications because they are lightweight, small, economic in energy, cheap and available in short delays. The reliability of MEMS COTS that are used out of their intended domain of operation (such as a space application) might be assured by a reliability methodology derived from the Physics of Failure approach. In order to use this approach it is necessary to create models of MEMS components that take into consideration environmental stresses and thus can be used for lifetime prediction. Unfortunately, today MEMS failure mechanisms are not well understood today and therefore a preliminary work is necessary to determine influent factors and physical phenomena. The model development is based on a good knowledge of the process parameters (Young’s modulus, stress...), environmental tests and appropriated modeling approaches, such a finite element analysis (FEA) and behavioural modeling. In order to do the environmental tests and to analyse MEMS behaviour, we have developed the Environmental MEMS Analyzer EMA 3D. The described methodology has been applied to a Commercial-off-the-shelf (COTS) accelerometer, the ADXL150. A first level behavioral model was created and then refined in the following steps by the enrichment with experimental results and finite element simulations.

System design methodology becomes a strategic activity in the industrial competition. Obtaining substantial reduction of time to market for complex and reliable products is one of the priorities for the manufacturers. Top down design, automated generation of architecture, co-design, virtual prototyping, etc. are already identified as research topics which have to be privileged. To be efficient, each theoretical contribution must be inserted in a global procedure of project management where complementary elements such as marketing, technico-economic survey, road-mapping, internal know-how,.. must be considered. In this context, this paper will present a design methodology starting from the requirement statement until the technical realization of the product, and applied to the design of a Time Stress Measurement Device for the observation of aeronautical mechanical systems.

Compactness, complexity of the interconnections and specific packaging, which are characteristics of Microsystems (MEMS), rule out the use of statistical procedure to assess reliability in space applications. Predictable reliability is the method recommended in this paper that uses a similar approach as CALCE already did for hybrid and microelectronic circuits. This method based on a failure mechanism approach is recalled at first and an example to illustrate this procedure based on the evolution of material crystal properties under radiation is presented.

The objective of the MICROMED CNRS project is the design of a complete microsystem usable in the treatment in vivo of hypertensives. The microsystem which corresponds with this objective includes different elements such as pressure sensors, a drug reservoir, a monitoring chip and a drug delivery system that necessitates the use of a dosing micropump able to deliver daily doses of few microliters in several shots. We'll focus here on the micropump: microfabrication technology, assembly and test. The fact that the fluid actuating membrane, the input and output fluid gates, and the two passive microvalves are together on a single silicon chip of 1cm 2 area makes this pump original. The fabrication technology combines the techniques of microelectronics and MEMS : micromachining for the square membrane (of 4x4mm 2 area and 40μm thick) and the fluid gates, sacrificial oxide layers and LPCVD polysilicon deposition for the microvalves. The assembly of the different parts (pump, membrane actuator and fluid chamber) is based on existing techniques like anodic bonding, gluing with adhesive films,...We have investigated the fabrication of the micropump with an electrostatic actuation. Tests are in progress for the first prototypes on a specific experimentation set-up in order to: (i) study the flowing of different fluids into the pump (water, propanol), (ii) study the directionality of the valves by plotting the flow rate/pressure Φ(P) diagram, (iii) study the pump functionality.

With the development of microspacecraft technology micropropulsion concepts are introduce for course correction, orbit insertion as well as attitude control of the microspacecraft. In this context, we have introduced a new concept of MEMS based technology microthruster responding to the spatial constraints and MEMS characteristics. The originality and advantages of these new thrusters is the use of only one solid propellant stored in a small tank micromachined in a ceramic or silicon substrate and the possibility of fabricating arrays of N addressable independently microthrusters in the same chip. The thrust force generated can be set from a few (mu) N to a few 150mN by geometrical and dimensional considerations. Fabrication and assembly of array of 16 microthrusters proved the technological feasibility and the functioning performances of this new concept of small scale thrusters.

The chemical analysis plays an important role in a clinical medicine. A small size of the analyzing system and reduced sample volume are required. Fully recognizing the benefits of this technology, we are working in the frame of a European project called BARMINT (basic research for microsystem integration) and is concerned with the development of a novel microsystem containing chemical and pressure sensors for the chemical analysis of fluids.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The implementation of an anticollision system on a car is presented. The vehicle is provided with two LIDAR systems integrated near the headlights, and a RADAR included in the calender, both used for active detection. Twelve infrared beacons have also been set up on the front part for telecommunication exchanges with surrounding vehicles or with infrastructure. An uncooled copolymer 32 X 32 FPA for passive detection has in addition been investigated for a further integration and is presented in this paper. This project is a part of the European PROMETHEUS-PROCHIP program which intends to make safer road traffic.

The first prototype using a silicon photodiode coupled with a pyroelectric sensor [1] has been modified to be set up on a car. Improvement has been achieved with the replacement of the IR PVDF material by a copolymer, which involves a new technology and a new poling procedure of the active device integrated on the Silicon chip. In addition, two other points are examined in this step : the design and the implementation of a 30 meter-range telemeter and the strategy of integration of the whole system.

The initial stages of the growth of CdTe on (100) GaAs with 14. 7 lattice mismatch has been simulated. It is shown that growth in (111) direction with the presence of twins is always preferred on perfect substrate surfaces. In the case of growth in (100) direction misfit dislocations are formed. The critical thickness is evaluated by extrapolation to be 6 - 8 atomic monolayers .

The polyvinylidene fluoride, PVCV, has demonstrated, since a few years, its better feasibility than that exhibited by ceramics in pyroelectric detection, and performances of discrete PVDF IR detectors have already been presented [1]. A new step toward the development of a focal plane matrix array is analyzed in this paper, in which technology and properties of a PVDF linear array are detailed. A first, advantages and drawbacks of the photolithography technique applied to PVDF are widely discussed and compared with the metal deposition using direct evaporation or sputtering through a metallic mask. Then, the use of the R.T. poling procedure developed by F. Bauer on a biaxially stretched PVDF is recalled. Finally, the technique used to elaborate a 10 pixels linear array, accounting for a proper selection of the polymer thickness is presented. Influence of this choice on the thermal cut off frequency, on the electrical cut off frequency and on the response of the elementary unit is determined and modelized. Characterization of tie whole structure, concerning response dispersion and cross talk between units and sensitivity of the linear array is analyzed. Results are shown to be most encouraging to prepare the next step dealing with the F.P. matrix array.

Parameters controlling the design of a pyroelectric PVDF matrix arrayVui V. Pham, Daniel Esteve, Essaid Bousbiat, Jean Farre, Rene Leguerre, Jean SimonneLaboratoire d'Automatique et d'Analyse des Systemes du C.N.R.S.7, ay. du Colonel Roche, 31077 Toulouse cedex, FranceAbstractPVDF, mostly investigated for its piezoelectric properties has been also demonstratedas a promising candidate for pyroelectric detection ; the challenge is to assess how far itsperformance can be brought to set the chance of development of PVDF infrared detectors tocivilian applications with regard to other conventional pyroelectrics.We have therefore elaborated discrete elements, linear arrays and test structures on9 to 40 4m thick materials to check the best conditions to be fulfilled in order to designa bidimensional array, with 8 x 8 elements to begin with.The poling process carried out on a biaxially strdched material with a slowly increa-sing a.c. electric field at room tempe5ature (the Bauer's method) insures the largestremanent polarization (around 10 4C /cm ) and its stability with time. Sensibility of freelymounted detectors decreases as an hyperbolic function of the thickness, while the thermalcut off time constant increases up to a limit reached at 25 µm. Influence of the pixel areaand spacing between cells on cross talk is also investigated on a multi -units array.Finally, design of a matrix is proposed.IntroductionAs infrared detection and imaging are promised to make a real breakthrough in the90's, thermal detection is to date considered as a true alternative way to quantum detec-tion in specific applications where ultimate detectivity is not required, like in driveand security in automotive, watching, alarm, medical controls and even in certain militaryapplications.In the same way ub MCT (Mercury Cadmium Telluride) is in competition with Silicides /Siin the 3 -5 4m range in cooled IR -FPA (Infra Red Focal Plane Array), PVDF (PolyvinylideneFluoride) is emerging in pyroelectrics, against ceramics, even if today the best perfor-mances of a 32 x 32 FPA have been achieved with a material of the _PZLT _lceramic familyEven though the pyroelectric coefficient of PVDF

Molecular Mechanics and Monte Carlo Methods have been applied to the modelling of a heteroepitaxy of CdTe on GaAs presenting a lattice mismatch of 14.7%. The growth of one monolayer has been simulated. The model is restricted to the analysis of defect creation at points of high strain. Creation of stable and unstable defects have been observed from the beginning of the growth in the case of a "soft" substrate.