High precision bulk micromachining of silicon is a key process step to shape spatial structures for fabricating different type microsensors and microactuators. A series etching experiments have been carried out using KOH, TMAH dual doped at etchant concentrations temperatures wherein silicon, dioxide aluminum etch rates together with <100> surface morphology <111>/<100> rate ratio investigated in each etchant. comparative study the etched roughness ambient also presented. From experimental...

A series of dicobalt complexes, Co2L(2+) and Co2LAc(+), where L is a N6O2 coordinating bis(phenolate) tetrakis-Schiff base ligand, have been synthesized characterized via electrochemical spectroscopic techniques. [Co2LAc](ClO4) crystallizes in the monoclinic space group P21/n, structure reveals highly distorted octahedral geometry for Co(II) ions, which are bridged by an acetate with Co-Co distance 3.2 Å. Cyclic voltammetry (CV) Co2LAc(+) anhydrous acetonitrile large anodic/cathodic peak...

The CMOS compatible bulk micromachined piezoresistive accelerometer presented in this paper consists of four flexures supporting a proof mass. Four pairs boron-diffused piezoresistors are located at maximum stress points on the near mass and frame ends. Because opposite nature two ends, these can be connected to form Wheatstone bridge such that off-axis responses practically cancelled while on-axis (along perpendicular mass) response is maximized. device simulated using CoventorWare. In...

Electroplated gold films have attracted much attention in recent years because of its desirable properties for microsystems applications such as resistance to oxidation, low electrical resistance, overall chemical inertness and processing temperature. In order use microelectromechanical systems designs, systematic tests has be conducted characterize the material terms well mechanical properties. this paper, stress resistivity behavior a nanometer-scale film with respect deposition parameters...

For a long time wet bulk-micromachining has been an easy and cost-effective method for fabricating silicon micro-sensors. Anisotropic etching is the key processing step fabrication of microstructures. Among different etchants, TMAH based etchants are becoming popular because their low toxicity CMOS compatibility. The etch rate anisotropic depends on crystal plane orientation, type etchant concentrations. In etching, convex corners attacked; therefore, proper compensating structure design...

The synthesis of Mn2LAc+, Zn2LAc+, and H4L2+ is described, where L a tetrakis-Schiff base macrocycle formed using 4-tert-butyl-2,6-diformylphenol 2,2′-diamino-N-methyldiethylamine resulting in an N6O2 coordination environment. In Mn2LAc+ the two metal centers are bridged by acetate ligand. [Mn2LAc](ClO4)·(DMF)0.5, [Mn2LAc](ClO4)·(ACN)0.5, [Zn2LAc](PF6) crystallized space group P21/c, with nearly identical unit-cell dimensions geometric structures. Electrochemical analysis cyclic voltammetry...

The fabrication of silicon based micromechanical sensors often requires bulk etching after aluminum metallization. All wet etchants including ordinary undoped tetramethyl ammonium hydroxide (TMAH)–water solution attack the overlaying metal interconnect during anisotropic (100) silicon. This paper presents a TMAH–water recipe to achieve high etch rate, smooth etched surface and almost total protection exposed rate measurements silicon, dioxide along with morphology studies surfaces are...

Convex corner undercutting in <100> silicon is an undesired phenomena during bulk micromachining of crystalline substrate using anisotropic wet chemical etching process. The present investigation concentrates on the studies convex at free end cantilever beams released by It also reports a simple, space efficient compensation design for complete prevention deformation. Various patterns such as square, rectangle and superposition square rectangular blocks various dimensions have been employed...

Empirical relations for the capacitive and inductive coupling coefficients have been used to compute normal-mode parameters of non-identical microstrip coupled lines. The computed values mode velocities impedances are compared with available results from literature experimental on nonidentical couplers test applicability empirical relations.

We report the synthesis of a Co(III) complex with five-coordinate salen-type ligand (N,N′-bis(3,5-di-tert-butyl-2-hydroxybenzyliden)-1,7-diamino-4-methyl-4-azaheptane). This is stable in air trigonal bipyramidal geometry and we show spectroscopically computationally that high-spin triplet ground state preferred. spin readily modulated by introduction an exogenous (pyridine, acetonitrile) to yield six-coordinate low-spin state. The exhibits solvent- ligand-dependent electrochemical behavior...

We have recently reported a new class of tetrakis-Schiff base macrocycles bearing dimanganese-oxo cluster capable catalyzing the oxidation water to O2. Herein we report applicability unrestricted density functional theory (DFT) using B3LYP hybrid and broken symmetry (BS) formalism for prediction thermodynamic properties proton-coupled electron transfer (PCET) steps involved in electrocatalytic cycle. characterize series three oxidations acetate-bound catalyst [MnII2LAc]+ acetonitrile...

Empirical relations for inductive and capacitive coupling coefficients are proposed. The functional relationships based on the physical mechanism of in microstrip lines. Values computed from even- odd-mode impedances phase velocities, available literature, compared with those proposed relations. Microstrip couplers have been designed basis to meet desired isolation.

This paper describes the modeling of a sensor suitable for biological applications using ISFET as primary device. Since sensors are based on field effect principles, standard equations MOSFET have been extended to and integrated with pH variation terms. The analysis from electro-chemistry point has presented low noise circuit complete designed. Simulated results verified experimental ones.

Single crystals of strontium undecazinc, SrZn(11), were obtained when decomposing SrZn(2) under conditions high pressure and temperature. The new binary Sr-Zn compound crystallizes in the space group I4(1)/amd (BaCd(11) structure type) with one Sr position (\overline{4}m2) three Zn sites (\overline{4}m2, .2/m., 1). is described terms all-face-capped Zn(8) tetrahedra as central building unit, defined by atoms on .2/m. 1. units are condensed into chains sharing edges, interconnected shared...

In this work, a field programmable gate array (FPGA) implementation of an automobile fuel control system is presented. The engine unit (ECU) described here uses new technique to injection rate through indigenously developed MEMS accelerometer sensor. A simple car model used show efficacy such with goal optimize efficiency and minimize toxic emissions. Hardware performances are provided simulation diagrams which can be considered as feasibility study results towards full-fledged solution.

This paper reports the design and simulation of two MEMS piezoresistive accelerometers for single axis low g (plusmn2g) automotive applications. Both accelerometer structures consist four beams at top with eight embedded resistors as sensing elements to form Wheatstone bridge network interconnected minimize cross sensitivity. FEM based results both are presented compared, which performed using commercially available MEMSCAD tool CoventorWarereg. Fabrication process technological aspects...

Unlike in capacitive accelerometers, where the output voltage is less sensitive to temperature effects, but piezoresistive accelerometers varies considerably with respect temperature. This paper presents drift analysis of silicon micromachined accelerometer. The input range accelerometer /spl plusmn/13 g and this device finds application aircraft motion sensing. simulated using MemPZR module CoventorWare 2003.1 simulation results are presented.