Design and analysis of RF MEMS shunt switch for V-band applications

Microsystem Technologies - In this paper, we have designed and simulations of RF MEMS shunt switch. The electro-mechanical and electromagnetic analysis of the switch have been done using COMSOL...     

Design,simulation and analysis of RF MEMS capacitive shunt switches with high isolation and low pull-in-voltage

Microsystem Technologies - This paper presents the design a capacitive shunt type RF-MEMS switch with high isolation, high switching speed and low actuation voltage for Ka-band applications. The...     

Distributed Symbolic Bounded Property Checking

In this paper we describe an algorithm for distributed, BDD-based bounded property checking and its implementation in the verification tool SymC. The distributed algorithm verifies larger models and returns results faster than the sequential version.The core algorithm distributes partitions of the state set to computation nodes after reaching a threshold size. The nodes proceed with image computation on the nodes asynchronously. The main scalability problem of this scheme is the overlap of state set partitions. We present static and dynamic overlap reduction techniques.     

Design,Performance Analysis of GaAs/6H-SiC/AlGaN Metal Semiconductor FET in Submicron Technology

Silicon - A unique structure of GaAs/6H-SiC/InGaN metal–semiconductor field-effect transistor has been proposed and demonstrated in this work. The proposed GaAs/6H-SiC/InGaNMetal...     

A Qualitative Review on Tunnel Field Effect Transistor- Operation,Advances, and Applications

Silicon - Tunnel Field Effect Transistor (TFET) has become one of the promising devices to be part of Integrated circuits as the technology advances to the nanoscale. A TFET has many advantages...     

De-Duplication Complexity of Fingerprint Data in Large-Scale Applications

De-duplication using biometrics has gained much attention from research communities as it provides a unique identity for each and every individual among the large population.De-duplication is the process of removing the instances of multiple enrollments by the same person using the person’s biometric data.An important issue in the large-scale de-duplication applications is the speed of matching and the accuracy of the matching because the number of persons to be enrolled runs into millions.This paper presents an efficient method to improve the accuracy of fingerprint de-duplication in de-centralized manner.De-duplication accuracy decreases because of the noise present in the data,which would cause improper slap fingerprint segmentation.In this paper,an attempt is made to remove the noise present in the data by using binarization of slap fingerprint images and region labeling of desired regions with 8-adjacency neighborhood.The distinct feature of this technique is to remove the noise present in the data for an accurate slap fingerprint segmentation and improve the de-duplication accuracy.Experimental results demonstrate that the fingerprint segmentation rate and de-duplication accuracy are improved significantly.     

Study of bimetallic corrosion related to Cu interconnects using micropattern corrosion screening method and Tafel plots

On-chip microscopic corrosion, originating from contact of dissimilar metals, can cause serious reliability issues for integrated circuits and microelectromechanical devices. A new micropattern corrosion screening method combined with Tafel plots were employed to study Cu bimetallic corrosion in acid and base solutions relevant to the chemical–mechanical planarization process. The results demonstrated that Cu corrosion on Ru is much more severe compared to Cu corrosion on Ta substrates. Tafel plots confirm the nobility trend of Ru > Cu > Ta. The micropattern corrosion study shows the Cu bimetallic corrosion depends on specific chemicals and bimetallic contacts. Strong complexing ligands like NH₃ combined with energetically favorable Cu/Ru bimetallic contact promote faster Cu corrosion under alkaline conditions (9 ≤ pH ≤ 11.4). Micropattern corrosion screening was shown to be useful in identifying the metastable surface layer during Cu corrosion and determining the optimal benzotriazole concentration for Cu corrosion inhibition.     

Mechanistic fracture criteria for the failure of human cortical bone

A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the microstructure affects the failure of bone is lacking. Although micromechanical models incorporating local failure criteria have been developed for metallic and ceramic materials, few such models exist for biological materials. In fact, there is no proof to support the widely held belief that fracture in bone is locally strain-controlled, as for example has been shown for ductile fracture in metallic materials. In the present study, we provide such evidence through a novel series of experiments involving a double-notch-bend geometry, designed to shed light on the nature of the critical failure events in bone. We examine how the propagating crack interacts with the bone microstructure to provide some mechanistic understanding of fracture and to define how properties vary with orientation. It was found that fracture in human cortical bone is consistent with strain-controlled failure, and the influence of microstructure can be described in terms of several toughening mechanisms. We provide estimates of the relative importance of these mechanisms, such as uncracked-ligament bridging.     

Parametric sensitivity study of operating and design variables in wellbore heat exchangers

A numerical study was conducted to evaluate the potential for using Wellbore Heat Exchangers (WBHX) to extract heat for use in electricity generation. Variables studied included operational parameters such as wellbore geometries, working fluid properties, circulation rates, and regional properties including basal heat flux and formation rock type. Energy extraction is strongly affected by fluid residence time, heat transfer contact area, and formation thermal properties. Water appears to be the most appropriate working fluid. The effects of tubing properties and casing lengths are of second-order.On the basis of a sensitivity study, a Best Case model was simulated, and results compared against the geothermal fluid requirements of existing power generation plants that use low-temperature geothermal fluids. Even assuming ideal work conversion to electricity, a WBHX cannot supply sufficient energy to generate 200 kWe at the onset of pseudo-steady-state (PSS) conditions. Using realistic conversion efficiencies it is unlikely that the system would be able to generate 50 kWe at the onset of PSS.     

Characteristic dimensions and the micro-mechanisms of fracture and fatigue in `nano' and `bio' materials

The behavior of small-volume (so-called `nano') structures, where size-scales are comparable with microstructural dimensions, and biological/bio-implantable materials, which invariably display a hierarchy of structural dimensions, is currently much in vogue in materials science. One aspect of this field, which to date has received only limited attention, is the fracture and fatigue properties of these materials. In this paper, we examine two topics in this area, namely the premature fatigue failure of silicon-based micron-scale structures for microelectromechanical systems (MEMS), and the fracture properties of mineralized tissue, specifically human bone.