Searcharxiv⌕ Search

SEARCH · Searcharxiv

Results for “cs.OH”

Search indexed arXiv papers on artificial intelligence, large language models, computer vision and robotics. Read source abstracts and follow links to arXiv.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

Applying Software Defect Estimations: Using a Risk Matrix for Tuning Test Effort

Applying software defect esimation techniques and presenting this information in a compact and impactful decision table can clearly illustrate to collaborative groups how critical this position is in the overall development cycle. The Test Risk Matrix described here has proven to be a valuable addition to the management tools and approaches used in developing large scale software on several releases. Use of this matrix in development planning meetings can clarify the attendant risks and possible consequences of carrying out or bypassing specific test activities.

cs.SE↗

Microsystem Product Development

Over the last decade the successful design and fabrication of complex MEMS (MicroElectroMechanical Systems), optical circuits and ASICs have been demonstrated. Packaging and integration processes have lagged behind MEMS research but are rapidly maturing. As packaging processes evolve, a new challenge presents itself, microsystem product development. Product development entails the maturation of the design and all the processes needed to successfully produce a product. Elements such as tooling design, fixtures, gages, testers, inspection, work instructions, process planning, etc., are often overlooked as MEMS engineers concentrate on design, fabrication and packaging processes. Thorough, up-front planning of product development efforts is crucial to the success of any project.

cs.OH↗

Parasitic Effects Reduction for Wafer-Level Packaging of RF-Mems

In RF-MEMS packaging, next to the protection of movable structures, optimization of package electrical performance plays a very important role. In this work, a wafer-level packaging process has been investigated and optimized in order to minimize electrical parasitic effects. The RF-MEMS package concept used is based on a wafer-level bonding of a capping silicon substrate to an RF-MEMS wafer. The capping silicon substrate resistivity, substrate thickness and the geometry of through-substrate electrical interconnect vias have been optimized using finite-element electromagnetic simulations (Ansoft HFSS). Test structures for electrical characterization have been designed and after their fabrication, measurement results will be compared with simulations.

cs.OH↗

Surface Conditioning Effect on Vacuum Microelectronics Components Fabricated by Deep Reactive Ion Etching

Advances in material processing such as silicon micromachining are opening the way to vacuum microelectronics. Two-dimensional vacuum components can be fabricated using the microsystems processes. We developed such devices using a single metal layer and silicon micromachining by DRIE. The latter technological step has significant impact on the characteristics of the vacuum components. This paper presents a brief summary of electron emission possibilities and the design leading to the fabrication of a lateral field emission diode. First measurement results and the aging of the devices are also discussed.

cs.OH↗

3-D Self-Assembled Soi Mems: An Example of Multiphysics Simulation

MEMS devices are typical systems where multiphysics simulations are unavoidable. In this work, we present possible applications of 3-D self-assembled SOI (Silicon-on-Insulator) MEMS such as, for instance, thermal actuators and flow sensors. The numerical simulations of these microsystems are presented. Structural and thermal parts have to be strongly coupled for correctly describing the fabrication process and for simulating the behavior of these 3-D SOI MEMS.

cs.OH↗

Influence of the Feedback Filter on the Response of the Pulsed Digital Oscillator

This paper introduces a new feedback topology for the Pulsed Digital Oscillator (PDO) and compares it to the classical topology. The `classic' or single feedback topology, introduced in previous works, shows a strong behavior dependence on the damping losses in the MEMS resonator. A new double feedback topology is introduced here in order to help solving this problem. Comparative discrete-time simulations and preliminary experimental measurements have been carried out for both topologies, showing how the new double feedback topology may increase PDO performance for some frequency ranges.

cs.OH↗

Concave Microlens Array Mold Fabrication in Photoresist Using UV Proximity Printing

This paper presents a simple and effective method to fabricate a polydimethyl-siloxane (PDMS) microlens array with a high fill factor, which utilizes the UV proximity printing and photoresist replication methods. The concave microlens array mold was made using a printing gap in lithography process, which utilizes optical diffraction of UV light to deflect away from the aperture edges and produces a certain exposure in the photoresist material outside the aperture edges. This method can precisely control the geometric profile of concave microlens array. The experimental results showed that the concave micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micron to 720 micron. High fill factor microlens array can be produced, when the control pitch distance between the adjacent apertures of the concave microlens array was decreased to the aperture size.

cs.OH↗

The annealing induced extraordinary properties of SI based ZNO film grown by RF sputtering

Pb(Zr0.52Ti0.48)O3 (PZT) thin films were in situ deposited by pulsed laser deposition (PLD) on Pt/Ti/SiO2/Si substrates using a template layer derived by sol-gel method. A 0.1-$μ$m-thick PZT layer with (111) or (100)-preferred orientation was first deposited onto Pt/Ti/SiO2/Si substrates using the sol-gel method, and than a PZT layer with thickness of 1$μ$m was in situ deposited by PLD on the above-mentioned PZT layer. The crystalline phases and the preferred orientations of the PZT films were investigated by X-ray diffraction analysis. Surface and cross-sectional morphologies were observed by scanning electron microscopy and transmission electron microscopy. The electrical properties of the films were evaluated by measuring their P-E hysteresis loops and dielectric constants. The preferred orientation of the films can be controlled using the template layer derived by the sol-gel method. The deposition temperature required to obtain the perovskite phase in this process is approximately 460 degrees C, and is significantly lower than that in the case of direct film deposition by PLD on the Pt/Ti/SiO2/Si substrates. Keywords: lead zirconate titanate (PZT), thin film, sol-gel method, laser ablation, electrical properties

cs.OH↗

Parametric Yield Analysis of Mems via Statistical Methods

This paper considers a developing theory on the effects of inevitable process variations during the fabrication of MEMS and other microsystems. The effects on the performance and design yield of the microsystems devices are analyzed and presented. A novel methodology in the design cycle of MEMS and other microsystems is briefly introduced. This paper describes the initial steps of this methodology that is aimed at counteracting the parametric variations in the product cycle of microsystems. It is based on a concept of worst-case analysis that has proven successful in the parent IC technology. Issues ranging from the level of abstraction of the microsystem models to the availability of such models are addressed

cs.OH↗

Electrostatically-Driven Resonator on Soi with Improved Temperature Stability

This paper deals with a single-crystal-silicon (SCS) MEMS resonator with improved temperature stability. While simulations have shown that the temperature coefficient of resonant frequency can be down to 1 ppm/degrees C, preliminary measurements on non-optimised structures gave evidence of a temperature coefficient of 29 ppm/degrees C. Design, optimisation, experimental results with post process simulation and prospective work are presented.

cs.OH↗

Electromechanical Reliability Testing of Three-Axial Silicon Force Sensors

This paper reports on the systematic electromechanical characterization of a new three-axial force sensor used in dimensional metrology of micro components. The siliconbased sensor system consists of piezoresistive mechanicalstress transducers integrated in thin membrane hinges supporting a suspended flexible cross structure. The mechanical behavior of the fragile micromechanical structure isanalyzed for both static and dynamic load cases. This work demonstrates that the silicon microstructure withstands static forces of 1.16N applied orthogonally to the front-side of the structure. A statistical Weibull analysis of the measured data shows that these values are significantly reduced if the normal force is applied to the back of the sensor. Improvements of the sensor system design for future development cycles are derived from the measurement results.

cs.OH↗

An Active Chaotic Micromixer Integrating Thermal Actuation Associating PDMS and Silicon Microtechnology

Due to scaling laws, in microfluidic, flows are laminar. Consequently, mixing between two liquids is mainly obtained by natural diffusion which may take a long time or equivalently requires centimetre length channels. To reduce time and length for mixing, it is possible to generate chaotic-like flows either by modifying the channel geometry or by creating an external perturbation of the flow. In this paper, an active micromixer is presented consisting on thermal actuation with heating resistors. In order to disturb the liquid flow, an oscillating transverse flow is generated by heating the liquid. Depending on the value of boiling point, either bubble expansion or volumetric dilation controlled the transverse flow amplitude. A chaotic like mixing is then induced under particular conditions depending on volume expansion, liquid velocity, frequency of actuation... This solution presents the advantage to achieve mixing in a very short time (1s) and along a short channel distance (channel width). It can also be integrated in a more complex device due to actuator integration with microfluidics.

cs.OH↗

Resolution Limits for Resonant Mems Sensors Based on Discrete Relay Feedback Techniques

This paper is devoted to the analysis of resonant MEMS sensors based on discrete relay feedback techniques. One drawback of such techniques is that some synchronization usually occurs between the discrete part and the continuous part of the system: this results in sensor responses that are very similar to the curves known as devil's staircases, i.e. the frequency does not vary smoothly with the sensor's input. The main contribution of this paper is a theoretical calculation of the resolution of such systems. The resolutions of two existing resonant MEMS architectures are then calculated and these results are discussed.

cs.OH↗

A Silicon-Based Micro Gas Turbine Engine for Power Generation

This paper reports on our research in developing a micro power generation system based on gas turbine engine and piezoelectric converter. The micro gas turbine engine consists of a micro combustor, a turbine and a centrifugal compressor. Comprehensive simulation has been implemented to optimal the component design. We have successfully demonstrated a silicon-based micro combustor, which consists of seven layers of silicon structures. A hairpin-shaped design is applied to the fuel/air recirculation channel. The micro combustor can sustain a stable combustion with an exit temperature as high as 1600 K. We have also successfully developed a micro turbine device, which is equipped with enhanced micro air-bearings and driven by compressed air. A rotation speed of 15,000 rpm has been demonstrated during lab test. In this paper, we will introduce our research results major in the development of micro combustor and micro turbine test device.

cs.OH↗

Energy Conversion Using New Thermoelectric Generator

During recent years, microelectronics helped to develop complex and varied technologies. It appears that many of these technologies can be applied successfully to realize Seebeck micro generators: photolithography and deposition methods allow to elaborate thin thermoelectric structures at the micro-scale level. Our goal is to scavenge energy by developing a miniature power source for operating electronic components. First Bi and Sb micro-devices on silicon glass substrate have been manufactured with an area of 1cm2 including more than one hundred junctions. Each step of process fabrication has been optimized: photolithography, deposition process, anneals conditions and metallic connections. Different device structures have been realized with different micro-line dimensions. Each devices performance will be reviewed and discussed in function of their design structure.

cs.OH↗

Above Ic Micro-Power Generators for RF-Mems

This work presents recent advances in the development and the integration of an electrochemical (chemicalelectrical energy conversion) micro power generator used as a high voltage energy source for RF-MEMS powering. Autonomous MEMS require similarly miniaturized power sources. Up to day, solid state thin film batteries are realized with mechanical masks. This method doesn't allow dimensions below a few mm^2 active area, and besides the whole process flow is done under controlled atmosphere so as to ensure materials chemical stability (mainly lithiated materials). Within this context, Microelectronics micro-fabrication procedures (photolithography, Reactive Ion Etching...) are used to reach both miniaturisation (100x100 $μ$m^2 targeted unit cell active area) and Above IC technological compatibility. All process steps developed here are realized in clean room environment.

cs.OH↗

Packaging of RF Mems Switching Functions on Alumina Substrate

Recently the strong demands in wireless communication requires expanding development for the application of RF MEMS (Radio Frequency micro electro mechanical systems) sensing devices such as micro-switches, tunable capacitors because it offers lower power consumption, lower losses, higher linearity and higher Q factors compared with conventional communications components. To accelerate commercialisation of RF MEMS products, development for packaging technologies is one of the most critical issues should be solved beforehand.

cs.OH↗

Recent Developments in Mems-Based Micro Fuel Cells

Micro fuel cells ($μ$-FC) represent promising power sources for portable applications. Today, one of the technological ways to make $μ$-FC is to have recourse to standard microfabrication techniques used in the fabrication of micro electromechanical systems (MEMS). This paper shows an overview on the applications of MEMS techniques on miniature FC by presenting several solutions developed throughout the world. It also describes the latest developments of a new porous silicon-based miniature fuel cell. Using a silane grafted on an inorganic porous media as the proton-exchange membrane instead of a common ionomer such as Nafion, the fuel cell achieved a maximum power density of 58 mW cm-2 at room temperature with hydrogen as fuel.

cs.OH↗