Recently, the requests for actuator are small size, high output power and lower electrical power, and so on. We are focusing on an electromagnetic type actuator. Nonetheless, this type actuator is known to be unsuitable for miniaturization because an allowable current carrying capacity is small. Therefore, we fabricated microcoil with narrow pitch and high aspect ratio using deep X-ray lithography and metallization techniques. If the aspect ratio is increased, cross section area of coil lines is also increased allowing a greater current path. We have fabricated coil lines with the width of 10 μm and the aspect ratio of over 5 on acrylic pipe surface. For current paths, copper layer was formed between narrow pitch thread structures on pipe by electroforming. Finally, isotropic copper etching was performed until the insulated portions of the wiring were exposed. We have estimated a suction force of electromagnetic actuator using this microcoil. The theoretical values by simulation and actual measurements of suction force were compared. These results are relatively in good agreement with theoretical values. Thus, it is very expected that microcoils with high aspect ratio and microactuators with high output force could be manufactured in spite of the miniature size.

This paper demonstrates a capacitive shunt type RF MEMS switch, which is actuated by electro-thermal actuator and electrostatic actuator at the same time, and than latching the switching status by electrostatic force only. Since thermal actuators need relative low voltage compare to electrostatic actuators, and electrostatic force needs almost no power to maintain the switching status, the benefits of the mechanism are very low actuation voltage and low power consumption. Moreover, the RF MEMS switch has considered issues for integrated circuit compatible in design phase. So the switch is fabricated by a standard 0.35um 2P4M CMOS process and uses wet etching and dry etching technologies for postprocess. This compatible ability is important because the RF characteristics are not only related to the device itself. If a packaged RF switch and a packaged IC wired together, the parasitic capacitance will cause the problem for optimization. The structure of the switch consists of a set of CPW transmission lines and a suspended membrane. The CPW lines and the membrane are in metal layers of CMOS process. Besides, the electro-thermal actuators are designed by polysilicon layer of the CMOS process. So the RF switch is only CMOS process layers needed for both electro-thermal and electrostatic actuations in switch. The thermal actuator is composed of a three-dimensional membrane and two heaters. The membrane is a stacked step structure including two metal layers in CMOS process, and heat is generated by poly silicon resistors near the anchors of membrane. Measured results show that the actuation voltage of the switch is under 7V for electro-thermal added electrostatic actuation.

Capacitive (condenser) MEMS microphones have been developed using various design and fabrication techniques to improve performance. Mechanical sensitivity of a condenser MEMS microphone can be increased by reducing the residual stress of the diaphragm using several design approaches including corrugated diaphragms, and in recent years, various spring type diaphragms. The electrical sensitivity of the condenser microphone is proportional to the deflection of the diaphragm, however, the parabolic deflection of the diaphragm, and thus its effective diaphragm area, has reduced the sensitivity of parallel plate type capacitor on a condenser MEMS microphone. This paper presents the numerical analysis on the effective diaphragm area of several condenser MEMS microphone designs of 1.1mm x 1.1mm square. The analysis shows that the effective area of a spring-supported diaphragm is about 20% higher, and its capacitance value thus electrical sensitivity, is about 170% higher than a fully clamped flat diaphragm of an equal size. In addition, a flat deflection and higher effective diaphragm area of a spring-supported diaphragm can be achieved by carefully designed spring mechanisms.

The object of this paper is to characterise the stiffness of microfabricated cantilevers consisting of two electroactive polymer (polypyrrole (PPy)) layers, and two gold layers with a negligible thickness and a layer of porous polyvinylidene fluoride (PVDF), which serves as a backing layer and electrolyte storage tank. This composite cantilever structure is used as polymer actuators or famously known as artificial muscles when tailored appropriately. The polymer microactuators considered in this study, which were fabricated using a laser ablation technique, could operate both in aqueous and non-aqueous media. The stiffness characterization of the microactuators is critical to assess their suitability to numerous applications including the micromanipulation of living cells, bio-analytical nanosystems, datastorage, labon- chip, microvalve, microswitch, microshutter, cantilever light modulators, micro-optical instrumentation, artificial muscles for micro and macro robotic sytems and similar. The stiffness measurement method followed in this study is a static deflection measurement method, using an atomic force microscope (AFM). The stiffness constants of the microactuators while they were in passive (no electrochemical activation) and active (electrochemically activated) states were measured separately, and their statistical comparison was provided. The possible error sources for the stiffness measurement method are elaborated.

The decreasing energy consumption of today's portable electronics has invoked the possibility of energy harvesting from ambient environment for self power supply. One common and simple method for energy harvesting is to utilize the direct piezoelectric effect. Compared to traditional piezoelectric materials such as lead zirconate titanate (PZT), macro-fiber composites (MFC) are featured in their flexibility of large deformation. However, the energy generated by MFC is still far smaller than that required by electronics at present. In this paper, an energy harvesting system prototype with MFC patches bonded to a cantilever beam is fabricated and tested. A finite element analysis (FEA) model is established to estimate the output voltage of MFC harvester. The energy accumulation procedure in the capacitor is simulated by using the electronic design automation (EDA) software. The simulation results are validated by the experimental ones. Subsequently, the electrical properties of MFC as well as the geometry configurations of the cantilever beam and MFC are parametrically studied by combining the FEA and EDA simulations for optimal energy harvesting efficiency.

3D stacking and integration can provide system advantages equivalent to up to two technology nodes of scaling. This paper explores memory rich applications for 3DIC. It shows how memory power and memory bandwidth can both be improved by an order of magnitude through 3D integration, and specifically explores a DSP application.

This paper compares the performance of first and second order time delay tanlock loop (TDTL) based integer frequency synthesizers. Varying the order of the loop changes the locking region of the complete system and affects the locking convergence. The synthesizer divider block also affects the system stability. Depending on the division factor the system may be driven outside its locking region. This is overcome by introducing an additional block that adaptively stabilizes the loop by driving it back to within the locking region. The results achieved indicate that the adaptive integer frequency synthesizers operate satisfactorily. The second order loop has shown to give a better acquisition performance when compared with the first order loop. This is due to the zero steady state phase error exhibited by the loop.

As the market size of mobile products is enlarged, low power and high density design in integrated chips are demanding. To meet these market demands, "ultra high density" (UHD) standard cell library becomes essential to further reduce the chip size. Furthermore, to enhance the density of standard cell library especially at 90nm and below, the conventional methods of reducing cell height is not sufficient to meet the density constraints. Motivated by the fact, in this paper, we devise a flexible design technique of UHD library with the multi-height cell structure. Each cell of conventional standard cell libraries with one-layer metal routing has the same cell height. However, multi-height cell library with two-layer metal routing has two types of cell structure: 1) Simple cells (e.g. inverter, nand, nor, etc.) are structured with single height; 2) Complex cells (e.g. flip-flop, latch, mux, etc.) are structured with double height. In this double height cell structure, Metal2 layer is used for power line. Therefore, Metal1 and G-ploy are routed vertically, gaining more Metal1 routing space, and thus we can attain more effective design for manufacturability (DFM). Also, by doing so, design time is reduced while achieving better layout efficiency. We tested logic circuits with 700,000 gates using 90nm technology to compare our new UHD library with existing high density library. Our experimental results show that each of 26 cells (frequently used) is shrunk by 14.29 ~ 26.98%. Furthermore, chip size is shrunk by 13.90 ~ 15.65% compared with high density library.

Adders are the core element in arithmetic circuits like subtracters, multipliers, and dividers. Optimization of adders can be achieved at device, circuit, architectural, and algorithmic levels. In this paper we present a new optimize full adder circuit structure that provides an improved performance compared to standard and mirror types adder structures. The performance of this adder in terms of power, delay, energy, and yield are investigated. This paper also proposes a novel simulation setup for full adder cells that is suitable for analyzing full adder cells at the high frequency. The simulation results of this structure will take into account the process variations for a 90 nm CMOS process and present results based on post-layout simulation using Cadence and Synopsys tools.

The double gate transistor is a promising device applicable to deep sub-micron design due to its inherent resistance to short-channel effects and superior subthreshold performance. Using both TCAD and SPICE circuit simulation, it is shown that the characteristics of fully depleted dual-gate thin-body Schottky barrier silicon transistors will not only uncouple the conflicting requirements of high performance and low standby power in digital logic, but will also allow the development of a locally-connected reconfigurable computing mesh. The magnitude of the threshold shift effect will scale with device dimensions and will remain compatible with oxide reliability constraints. A field-programmable architecture based on the double gate transistor is described in which the operating point of the circuit is biased via one gate while the other gate is used to form the logic array, such that complex heterogeneous computing functions may be developed from this homogeneous, mesh-connected organization.

This paper introduces a defect tolerant 64-bit Sklansky prefix adder, designed with the goal of increasing its reliability and extending its lifetime in the presence of hard faults. We consider defect tolerance for early transistor wear-out by exploring the design of fine-grained reconfigurable logic. The approach involves enabling spare processing elements to replace defective elements. Power gating techniques are used to disable faulty logic blocks and enable spare logic. Minimum sized transistors are used for spare processing elements to reduce area overhead, and simplify reconfiguration interconnect. The performance of the design is compared to a baseline, non-repairing design using the cost metrics of: area overhead, power consumption, and performance in the fault free and faulty case.

We present simultaneous fabrication of micro-deflector and optical waveguide using femtosecond two photon polymerization technique. Parallelepiped-shaped waveguide was created which may serve as beam deflectors for layerto- layer optical interconnection. The quality of the polymerized surface was characterized by atomic force microscope (AFM) which shows the root-mean-square (RMS) roughness is no greater than 5nm. The propagation and reflection loss of the fabricated waveguide at wavelength of 850nm are estimated to be <1dB/cm and <1.5dB per reflection, respectively. Based on this result, the total layer-to-layer insertion loss was estimated to be less than 4dB/cm, demonstrating the great potential for optical interconnections on printed circuit boards (PCBs).

A practical optical link system was prepared with a transmitter (Tx) and receiver (Rx) for reducing EMI (electromagnetic interference). The optical TRx module consisted of a metal optical bench, a module printed circuit board (PCB), a driver/receiver IC, a VCSEL/PD array, and an optical link block composed of plastic optical fiber (POF). For the optical interconnection between the light-sources and detectors, an optical wiring method has been proposed to enable easy assembly. The key benefit of fiber optic link is the absence of electromagnetic interference (EMI) noise creation and susceptibility. This paper provides a method for optical interconnection between an optical Tx and an optical Rx, comprising the following steps: (i) forming a light source device, an optical detection device, and an optical transmission unit on a substrate (metal optical bench (MOB)); (ii) preparing a flexible optical transmission-connection medium (optical wiring link) to optically connect the light source device formed on the substrate with the optical detection device; and (iii) directly connecting one end of the surface-finished optical transmission connection medium with the light source device and the other end with the optical detection device. Electronic interconnections have uniquely electronic problems such as EMI, shorting, and ground loops. Since these problems only arise during transduction (electronics-to-optics or opticsto- electronics), the purely optical part and optical link(interconnection) is free of these problems. 1 An optical link system constructed with TRx modules was fabricated and the optical characteristics about data links and EMI levels were measured. The results clearly demonstrate that the use of an optical wiring method can provide robust and cost-effective assembly for reducing EMI of inter-chip interconnect. We successfully achieved a 4.5 Gb/s data transmission rate without EMI problems.

Pt/anodized TiO2/SiC based metal-oxide-semiconductor (MOS) devices were fabricated and characterized for their sensitivity towards propene (C3H6). Titanium (Ti) thin films were deposited onto the SiC substrates using a filtered cathodic vacuum arc (FCVA) method. Fluoride ions containing neutral electrolyte (0.5 wt% NH4F in ethylene glycol) were used to anodize the Ti films. The anodized films were subsequently annealed at 600 °C for 4 hrs in an oxygen rich environment to obtain TiO2. The current-voltage (I-V) characteristics of the Pt/TiO2/SiC devices were measured in different concentrations of propene. Exposure to the analyte gas caused a change in the Schottky barrier height and hence a lateral shift in the I-V characteristics. The effective change in the barrier height for 1% propene was calculated as 32.8 meV at 620°C. The dynamic response of the sensors was also investigated and a voltage shift of 157 mV was measured at 620°C during exposure to 1% propene.

Zinc oxide (ZnO) is one of the most promising electronic and photonic materials to date. In this work, we present an enhanced ZnO Schottky gas sensor deposited on SiC substrates in comparison to those reported previously in literature. The performance of ZnO/SiC based Schottky thin film gas sensors produced a forward lateral voltage shift of 12.99mV and 111.87mV in response to concentrations of hydrogen gas at 0.06% and 1% in air at optimum temperature of 330 ºC. The maximum change in barrier height was calculated as 37.9 meV for 1% H2 sensing operation at the optimum temperature.

A gas sensor was developed by depositing polythiophene nanofibers on the surface of ZnO/36° YX LiTaO₃ layered surface acoustic wave (SAW) transducer and tested towards different concentrations of hydrogen gas in synthetic air. Polythiophene nanofibers were synthesized by using a template-free method through the introduction of an initiator into the reaction mixture of a rapidly mixed reaction between the monomer (thiophene) and the oxidant. The yield of the reaction was characterized using scanning electron microscopy (SEM) as well as Ultraviolet-visible (UV-vis) and Fourier Transform Infrared (FTIR) spectroscopies. The frequency shift due to the sensor response was ~17 kHz towards 1% of H2. All tests were conducted at room temperature. The sensor performance was assessed over a two day period and a high degree of repeatability was obtained.

Fundamental research and development in smart materials and structures have shown great potential for enhancing the functionality, serviceability and increased life span of civil and mechanical infrastructure systems. Researchers from diverse disciplines have been drawn into vigorous efforts to develop smart and intelligent structures that can monitor their own conditions, detect impending failure, control damage and adapt to changing environments. Smart structures are generally created through synthesis by combining sensing, processing and actuating elements integrated with conventional structural materials. The conventional non-destructive evaluation techniques are not very effective in monitoring the structural integrity of composite structures due to their micro-mechanical complexities. With the commercial availability of the magnetostrictive (MS) material Terfenol-D in particulate form, it is now feasible to develop particulate sensors to detect damage with minimum effect on structural integrity. In present investigation, the electromagnetic response in the MS layer at the onset of delamination in one of the weakest ply of the composite laminate has been analyzed. For the numerical analysis symmetric and asymmetric carbon epoxy laminates with one of its layers embedded with Terfenol-D particles have been taken. Terfenol-D layer experiences a change in stress due to onset of delamination causing a change in its magnetic state, which can be sensed as induced open circuit voltage in the sensing coil enclosing the laminate beam. The effect of material properties, lamination schemes and placement of MS layer on the sensing capabilities has been analyzed.

In this paper, a novel MEMS accelerometer based fuel control system for automobile applications has been presented, primarily to be used in Engine Control Unit (ECU). It consists of a MEMS accelerometer inertial sensor for acceleration/velocity measurement of automobile followed by a dedicated signal conditioning unit, data converter and fuel control unit. MEMS accelerometer implemented in this work is an application specific low-g single axis piezoresistive bulk micromachined device with very low cross-axis sensitivity, and fabricated using post-process CMOS compatible dual-dope (Silicic acid +Ammonium per Sulphate) TMAH anisotropic etching. Signal conditioning circuit is a chopper stabilized (CS) low noise amplifier suitable for low frequency low amplitude signal amplification. Data converter is a low power, 6-bit successive approximation (SAR) ADC. Circuit is designed in 0.18 µm CMOS technology. PID based control unit, which regulates the duration of fuel injection depending on the driver's request in real time for optimal efficiency and minimal pollution, has been developed in Simulink module.

A MEMS hot wire anemometer consisting of thermoresistive elements arranged in a differential bridge configuration is presented. The arrangement of the elements allows for dedicated heating elements to be omitted from the device without compromising operation or accuracy. Overall power consumption gives velocity and the temperature differential of each element pair is used for direction and has demonstrated a sensing resolution better than 1% and a repeatable accuracy better than 2%. Field trials have demonstrated a robust design with exposure to rain, dust and debris for a period in excess of 12 months with continuing operation.

In this paper, a preconcentrator-based sensor &mgr;-system for low level benzene detection is presented. It consists of a spiral-shaped &mgr;-reconcentrator with dimensions of 10cm × 300&mgr;m × 300&mgr;m, followed by a &mgr;-hotplate sensor matrix. The &mgr;-preconcentrator was fabricated on a silicon wafer by means of DRIE and anodic bonding techniques. To obtain the concentration factor of the fabricated devices, a GC/MS: Shimadzu-QP5000 equipment was used. The results obtained showed excellent repeatability and preconcentration factors up to 286. A considerable improvement (1500%) in the sensor responses was achieved with Pd doped SnO2 sensors. The small size of the manufactured devices enables their incorporation in an integrated GC/MS gas sensor system.

A smart micro-cantilever in a creative gas sensor with high sensitivity is presented. The resonance frequency shifting of the cantilever is monitored to detect its mass change caused by adsorption of certain gas molecules. The cantilever has a more compact MEMS structure and the smart functions because of the sensor with a self-actuating and detecting (SAD) vibration system, which is integration of a vibration actuating system and a detecting system. The model of the smart beam is analyzed by computer simulation. Design rules of the beam are obtained according to related discuss with function goal of extremely rare gas detection. After fabrication and test of the smart cantilever, an improved solution of the smart cantilever is introduced by comparison study of the computer simulation and experiment results of the fabricated beam.

Enhanced symmetrical self-aligned double-gate (DG) vertical nMOSFET with low parasitic capacitance is presented. The process utilizes the oblique rotating ion implantation (ORI) method combined with fillet local oxidation (FILOX) technology (FILOX + ORI). Self-aligned region forms a sharp vertical channel profile that increased the number of electrons in the channel. These have improved drive-on current and drain-induced-barrier-lowering (DIBL) effect with a reduced off-state leakage current tremendously. The gate-to-drain capacitance is significantly reduced while having a small difference of gate-to-source capacitance compared to FILOX device. The drain overlap capacitance is a factor of 0.2 lower and the source overlap capacitance is a factor of 1.5 lower than standard vertical MOSFETs.

An approximate analytical solution involving the evaluation of the overlap integral method has been developed to estimate the coupled optical power in a multilevel optical system. The transmitter and receiver optics are located on different planes, vertically separated by a distance Z. 45º micro-mirror pairs are used to facilitate out-of-plane reflection of the optical beam in order for the transmitter and receiver components to be optically linked. The optical components consist of planar waveguide focusing elements, involving a combination of graded-index effect and lens front curvature. Optical signal in many active and passive optical devices can be well approximated by a Gaussian beam. The coupling loss formulas have been derived to support elliptical and circular Gaussian beam analysis. Spot size mismatch, non-ideal propagation distance, axial offset, mirror angular deviation and relative tilt between the two planes are major contributors toward optical power loss in a multilevel optical system. The derived coupling loss formulas has been applied to find the optimal coupling condition like micro-mirror positions, Z, relative distances of optical elements from the micro-mirror, beam spot size, etc. for a prototype system. BPM simulation results are in good agreement with the numerical results obtained by the approximate analytical solutions. The derived coupling loss formulas can be used to estimate optimal optical power loss in a single level or multilevel optical system in MOEMS based optical circuits as well as in a conventional optical system where paraxial approximation is assumed.

Inductive power links are a popular method of wirelessly transferring power to small devices. High efficiency power transmitters such as the Class-E transmitter are the preferred choice for frequencies up to the low MHz range, however at frequencies above 100 MHz, the circuit does not produce a high enough efficiency. This paper investigates the consideration of parasitic elements of the transmission coils in the circuits, showing an improvement in the circuit's performance.

Vibration harvesting has been intensively developed recently and systems have been simulated and realized, but real-life situations (including aircraft Structure Health Monitoring (SHM)involve uneven, low amplitude, low frequency vibrations. In such an unfavorable case, it is very likely that no power can be harvested for a long time. To overcome this, multi-source harvesting is a relevant solution, and in our application both solar and thermal gradient sources are available. We propose in this paper a complete Microsystem including a piezoelectric vibration harvesting module, thermoelectric conversion module, signal processing electronics and supercapacitor. A model is proposed for these elements and a VHDL-AMS simulation of the whole system is presented, showing that the vibration harvesting device alone cannot supply properly a SHM wireless node. Its role is nevertheless important since it is a more reliable source than thermoelectric (which depends on climatic conditions). Moreover, synergies between vibration harvesting and thermoelectric scavenging circuits are presented.

The displacement of the moveable end bearing of a bridge is a very critical item that must be measured when evaluating the behavior of a bridge that might be affected by a falling deck or temperature variations, and the movement of the bearing shoe must be periodic monitored by maintenance personnel. But this type of monitoring method is inefficient since the maintenance personnel must perform the inspection in close proximity to the bridge substructure, which takes time and effort. So, for efficient maintenance, inspectors must be able to monitor the bearing shoe without proximity to substructure, which will necessitate the development of a reliable, movable end bearing monitoring system that is convenient for maintenance or monitoring personnel. However, with the existing system, the cabling is very complex and the noise affected by electromagnetic waves might occur. For this reason, this study was intended to develop the sensor system to monitor the displacement of the movable end bearing, using optical fiber sensor, which is durable and is not affected by electromagnetic waves. To that end, an optical fiber measuring device for monitoring the displacement of movable end bearing was developed, and a displacement-measuring algorithm, that uses measured data, was accordingly proposed. The monitoring system that was developed in the study is able to comprehensively collect the displacement data of the movable end bearing without the need to approach the substructure of the bridge by the maintenance personnel. Moreover, thanks to the high reliability of the data, it is expected to significantly enhance the work efficiency as well.

In this study, a portable type HMS (Health Monitoring System) device is newly developed. It has features 1) puncturing a blood vessel by using a minimally invasive micro-needle, 2) extracting and transferring human blood and 3) measuring blood glucose level. This miniature SMBG (Self-Monitoring of Blood Glucose) device employs a syringe reciprocal blood extraction system equipped with an electro-mechanical control unit for accurate and steady operations. The device consists of a) a disposable syringe unit, b) a non-disposable body unit, and c) a glucose enzyme sensor. The syringe unit consists of a syringe itself, its cover, a piston and a titanium alloy micro-needle, whose inner diameter is about 100µm. The body unit consists of a linear driven-type stepping motor, a piston jig, which connects directly to the shaft of the stepping motor, and a syringe jig, which is driven by combining with the piston jig and slider, which fixes the syringe jig. The required thrust to drive the slider is designed to be greater than the value of the blood extraction force. Because of this driving mechanism, the automatic blood extraction and discharging processes are completed by only one linear driven-type stepping motor. The experimental results using our miniature SMBG device was confirmed to output more than 90% volumetric efficiency under the driving speed of the piston, 1.0mm/s. Further, the blood sugar level was measured successfully by using the glucose enzyme sensor.

Piezoelectric ceramic lead zirconate titanate (PZT) based electromechanical impedance (EMI) technique has been applied for structural health monitoring (SHM) of various engineering systems. However, study on identification of damage severity and location is still in need. In the EMI method, the PZT electromechanical (EM) admittance is used as a damage indicator. Statistical techniques such as root mean square deviation (RMSD) have been employed to associate the damage level with the changes in the EM admittance signature. To achieve high sensitivity to damage, high frequency signatures (>200 kHz) have been used to monitor the region close to the PZT location. It has been reported that the use of RMSD as the damage indicator is difficult to specify the damage location and severity due to the inconsistency in the RMSD results. This paper proposes the use of large frequency (30-400 kHz) range and the RMSD values of sub-frequency intervals to eliminate the inconsistency in the results. An experiment is carried out on a real size concrete structure subjected to artificial damages. The PZT admittance signatures in a frequency range of 30 to 400 kHz for various structural damages have been recorded and the RMSD values of sub-frequency intervals of 10 kHz are calculated. Results show less inconsistency and uncertainties compared to the traditional method using limited high frequency range. It is observed that the damage close to the PZT changes the RMSD at high frequency range significantly; however the damage far away from the PZT changes the RMSD at low frequency range significantly.

Acoustic sensors are used in Structural Health Monitoring (SHM) for the detection of impacts and strain. However, secondary damage may result from the initial damage. This secondary damage, such as delamination or cracking, may not be detectable by the SHM system. This is a significant problem for passive sensing systems, such as those based on fibre optics, where signals cannot be actively generated to interrogate the structure. The integration of NDE by robotic agents into a SHM sensor network enables the detection and monitoring of a wider variety of damage. Communicating via acoustic transmissions represents a wireless communication method for robotic agents to communicate to the SHM system without the addition of extra hardware, as piezoelectric transducers are commonly used in NDE. The effect of Carbon Fibre Composites (CFC) on the ability to use acoustic transmission needs to be determined. We present results for the detection of Acoustic Emissions and Transmissions (AET) in a CFC laminate. The optical fibre AET detector was a Fibre Bragg Grating (FBG). Two FBG AET sensors were compared, one coupled to the surface of the carbon fibre sheet, and one embedded within the lay-up. Results compare the transfer function, frequency response, and transient response of the sensors. The embedded FBG receiver was also used to detect an actively generated acoustic transmission. A piezoelectric receiver was also used for comparison. The embedded FBG was found to give significantly better performance in all of the parameters considered for the surface coupled FBG.

A gas-flow device consisting of a valveless micro jet pump and flow sensor has been designed and fabricated using a Si micromachining process. The valveless micro pump is composed of a piezoelectric lead zirconate titanate (PZT) diaphragm actuator and flow channels. The design of the valvless pump focuses on a crosss junction formed by the neck of the pump chamber and one outlet and two opposite inlet channnels. The structure allows differences in the fluidic resistance and fluidic momentum inside the channels during each pump vibration cycle, which leads to the gas flow being rectified without valves. Before the Si micro-pump was developed, a prototype of it was fabricated using polymethyl methacrylate (PMMA) and a conventional machining techinique, and experiments on it confirmed the working principles underlying the pump. The Si micro-pump was designed and fabricated based on these working principles. The Si pump was composed of a Si flow channel plate and top and botom covers of PMMA. The flow channels were easily fabricated by using a silicon etching process. To investigate the effects of the step nozzle structure on the gas flow rate, two types of pumps with different channel depths (2D- and 3D-nozzle structures) were designed, and flow simulations were done using ANSYS-Fluent software. The simulations and excperimental data revealed that the 3D-nozzle structure is more advantageous than the 2D-nozzle structure. A flow rate of 4.3 ml/min was obtained for the pump with 3D-nozzle structure when the pump was driven at a resonant frequency of 7.9 kHz by a sinusoidal voltage of 40Vpp. A hot wire was fabricated as a gas-flow sensor near the outlet port on the Si wafer.

Real-time multi-objects labeling, which includes segmenting target, picking up features and labeling object automatically, is a study field of Automatic Target Recognition (ATR). Labeling object in an image is a very important step in many application areas such as target scouting and tracking, circuit board and IC mask inspection, environmental and medical image analysis. In this paper, the approaches on object description are classified. Based on the comparison of different methods in many aspects, some representative methods on object labeling, including their basic principles, characteristics, and drawbacks are researched. At the same time, one optimized technique, fast object description on multi-objects labeling, is presented. This fast object labeling algorithm is based on the pixel labeling method. Using the neighboring relationship of binary pixel points in the contiguous scanning lines, this fast approach can complete the pick-up of object labels and the combination of equal target labels during scanning once. Finally, in this approach, the labeling of objects and pick-up of features are accomplished. Experimental results show that the improved algorithm can be used to segment object and label multi-targets, and the performance of the algorithm is fast-speed, practical and simple as well as with the high ability of processing complex patterns.

Traditional optical image processing system is mostly based on PC, and is restricted in many fields. A novel system of optical image processing is advanced. It consists of two parts: image acquisition system and image processing system. Image acquisition system is made up of FPGA, CMOS image sensor and image buffer memory. DSP is selected as the key element of the image processing system. An extra image buffer memory and an image memory are also used. Program of optical image processing is written into DSP. Images processed can also be transmitted to display interfaces, such as LCD, TV, etc. The system can operate conveniently, smoothly and inerrably with high speed and precision.

As wireless devices proliferate, more of these devices have to share a finite and increasingly limited amount of available radio spectrum. Currently, spectrum bands are used for a particular purpose that they are licensed for. However, these spectrums are not always used by their licensees or primary users, and as such are unused and are idle most of the time. These swath of unused frequency spectrum can be used by unlicensed users, when available, to mitigate the spectrum scarcity. In this article we study different methods of spectrum sensing in cognitive radio paradigm and compare them in terms of their potential interference with primary users.

Low power sensor nodes distributed over a large geographical area provide an economical way to collect environmental information. The sensors can utilize backscatter signals to communicate with a central node without significant power consumption. Each sensor can modulate its reflected backscatter signal by switching a load on the sensor antenna. This allows design of low power sensor nodes with longer lasting battery life. The nodes can be built to reradiate a harmonic of the received signal. This helps to avoid interference at the central node from reflection from unwanted objects. A passive harmonic reradiator is designed in this project to receive a 915 MHz electromagnetic wave and reradiate at 1.83 GHz. The design consists of receiver antenna, transmitter antenna, a Schottky diode, and matching network. Simulation and measurement results are provided. The results show promising characteristics for the use of the device to track animals in wild life.

A wireless batteryless piezoresistive pressure sensing system was presented. The sensing system adapts RFID operation principles including a transponder and a reader. The transponder device includes an energy harvesting circuit, force sensing resistors, a resistance-to-frequency converter, and an antenna. The reader provides radio frequency power to the device remotely and measures the sensor values in terms of frequency shift simultaneously. The performance of the system was characterized form 0 to 10 psi while the corresponding modulated frequency shift by the reader was between 7.35 kHz and 8.55 kHz. A pressure sensor array was arranged to identify high pressure points dynamically for long-term usage.

A passive strain sensor was investigated using patch antennas. For early damage detection in structures due to external loads, reliable strain information is necessary. A noninvasive method of measuring strain using a patch antenna was investigated to overcome the limitations of existing strain sensing technologies. The metal patch antenna was made on a thin sheet of low-loss polymer with a ground plane on the opposite side. When fed with RF signals, the patch antenna radiates at its resonant frequency. The resonant frequency of the patch antenna varies with its dimensions. Strain-induced change in the dimensions results in a shift in the resonant frequency. A single-frequency antenna, designed and simulated using the Sonnet simulation tool, has a resonant frequency corresponding to its length, so the antenna is sensitive only to the length-direction strain yet insensitive to the width-direction strain. Effect of strain on frequency shift and its sensitivity to strain were calculated. The antenna was fabricated using conventional micromachining techniques. Effects of strain on resonant frequency were verified experimentally and in good agreement with simulated results.

In this work, three useful techniques for dynamic motion characterization of MEMS devices are presented, namely network analyzer, acoustic phonon detection and stroboscopic SEM techniques. Proof-of-concept experiments using an MEMS electrostatic resonator reveal reliable and consistent measurement results from the three techniques. The network analyzer characterization technique is most widely used in practice due to its convenience, high sensitivity and high speed. The second acoustic phonon technique features non-invasive and package level testing, but it is still an indirect characterization method, like the network analyzer. In acoustic phonon detection, mechanical waves (phonons) generated by the actuated MEMS device are used as the coupling mechanism through which information on the dynamic mechanical state of the device can be obtained. The third stroboscopic SEM technique is capable of directly measuring the device motion, but its throughput is low and hence not suitable for high volume testing. The stroboscopic SEM imaging system is based on time-gated sampling of the analogue secondary electron (SE) signal. Unlike conventional SEM, stroboscopic SEM is able to detect the actual position of the structure at a specific point in time by taking a time-gated sample of the SEM SE signal at a specific phase of the structure's motion.

Based on optical fiber grating sensing technology, the signal processing system of smart clothes was designed. The clothes embedded in fiber Bragg gratings (FBGs) sensor can measure the body physiological parameters, such as temperature, and detect the healthy condition of wearer. The paper presented FBG wavelength detection and signal processing methods with wearable characteristics, designed optical scheme and demodulated circuit in terms of tunable F-P filer wavelength demodulation theory. The numerical arithmetic of processing wavelength data was researched and realized in ARM. By testing, the measuring scope of wavelength is from 1520.5 to 1562nm, and the resolution of wavelength can arrive at 2pm. By selecting appropriate center wavelength of sensing gratings and referenced gratings, the relative error of wavelength can less than 0.001%. The signal processing system can adjust the excursion of F-P cavity timely, and has characters of portability, wireless data transmission.

Yield has always been a driving consideration during fabrication of modern semiconductor industry. Statistically, the largest portion of wafer yield loss is defective scan failure. This paper presents efficient failure analysis methods for initial yield ramp up and ongoing product with scan diagnosis. Result of our analysis shows that more than 60% of the scan failure dies fall into the category of shift mode in the very deep submicron (VDSM) devices. However, localization of scan shift mode failure is very difficult in comparison to capture mode failure because it is caused by the malfunction of scan chain. Addressing the biggest challenge, we propose the most suitable analysis method according to scan failure mode (capture / shift) for yield enhancement. In the event of capture failure mode, this paper describes the method that integrates scan diagnosis flow and backside probing technology to obtain more accurate candidates. We also describe several unique techniques, such as bulk back-grinding solution, efficient backside probing and signal analysis method. Lastly, we introduce blocked chain analysis algorithm for efficient analysis of shift failure mode. In this paper, we contribute to enhancement of the yield as a result of the combination of two methods. We confirm the failure candidates with physical failure analysis (PFA) method. The direct feedback of the defective visualization is useful to mass-produce devices in a shorter time. The experimental data on mass products show that our method produces average reduction by 13.7% in defective SCAN & SRAM-BIST failure rates and by 18.2% in wafer yield rates.

In this paper the switching of a proposed Stationary Optical Delay Line (SODL) is demonstrated. This is intended for proof of principle of the switching associated with such a SODL, to be applied to an Optical Coherence Tomography (OCT) system.. The proposed SODL is made up of one dimensional beam expanding cylindrical lenses, a liquid crystal transmissive Spatial Light Modulator (SLM), and a Stepped Mirrored Structure (SMS). The SLM is to be used as an addressable optical switch. The SMS is an array of staggered mirrored steps, where the step height corresponds to half the optical delay length. The required delay length from the SMS can then be selected with the SLM. In this work, beam expanding optics and a nematic Liquid Crystal Display (LCD) are used to demonstrate the ability to select a spatial region consisting of a row of 4 photodiodes substituting for the SMS. The principle of conventional sequential switching, depth hoping, and multicasting of the four windows generated on the SLM are demonstrated. Rise and fall times were 260 and 150 ms, sufficient to prove the principle of switching at 1Hz. A maximum of 2 Hz could be achievable without detriment to the contrast ratio. The contrast ratios between transparent and opaque LCD window states was 2.4 ± 0.2. The contrast ratios between transparent and light-off states was 23 ± 4. Hence, the contrast ratios between opaque and light-off states was 9 ± 1. These values were within the expected ranges for nematic LC SLMs.

Optical fiber distributed sensors hold great promise for corrosion monitoring in large structures. Systems based on absorption losses are relatively well developed, whereas fluorescence systems have been comparatively neglected due to the low efficiency of coupling light emitted in the cladding back into the core. This paper presents a model distributed corrosion sensor based on fluorescence detection by photon counting. The model predicts sufficient sensitivity for practical application under ideal conditions. Preliminary experimental results suggest that additional factors such as scattering at the core-cladding interface and mode distribution effects can have a significant deleterious effect on the performance in practice.

In this paper we present an introduction to Cognitive RFID Integrated System Platform (CRISP), a framework for development and implementation of RFID communication protocols. The framework enables advanced research in the area of RFID wireless communication protocols and algorithms by interfacing a large class of experimental medium access control (MAC) with custom physical layer (PHY) implementations. As such, CRISP provides a flexible, scalable, configurable and high performance RFID research tool. The low level protocol handling routines are written in VHDL and higher level functions are programmed in C and targeted to embedded Microblaze soft-core processor within the Xilinx Virtex 5 class of FPGAs. Furthermore, the online open-access repository from The University of Adelaide is available to document and share different architecture and designs with other researchers in the field.

For modelling molecular electronic and electrochemical boundary value problems (BVPs), we are faced with the solution of Schrodingers equation involving realistic models for potential energy functions. With the exception of a few canonical problems, there are currently no analytical methods available for obtaining closed-form solutions for the electron wavefunctions and their corresponding energy eigenvalues. One of the well-known techniques for obtaining approximate wavefunctions and energy states is the WKB approximation. The main drawbacks of the WKB method are the discontinuities at the so called turning points, where the total energy equals the potential energy and the restriction on exclusively solving for bound state solutions. To overcome these shortcomings, a novel accelerated numerical technique for solving time-independent Schrodingers equation is introduced, with applications to general potential functions. This method is based on the construction of an auxiliary BVP, which mimics significant features of the original BVP and possesses exact solutions. By construction, these solutions constitute a complete set of orthogonal problem-adapted analysing functions. This method provides numerical solutions with no discontinuities at the turning points.

This paper presents the design and implementation of a fully on-chip wideband low noise amplifier (LNA) using 0.25- micron Silicon-on-Sapphire (SOS) technology for the next-generation Square Kilometre Array (SKA) radio telescope application. Ultra low noise and wideband operation are the principle design challenges in LNA for SKA application. The proposed LNA design employs cascaded inductive degeneration architecture and achieves broadband matching by using on-chip high quality factor (Q) SOS inductors inter-stage/intermediate LC matching circuit. Use of high Q inductors results in low noise input matching circuit that enables the LNA to achieve the required minimum noise figure (NF). The proposed LNA is a complete on-chip solution that achieves a NF from 0.57dB to 0.68dB over 1.1GHZ-band with a minimum gain of 15.3dB. This design consumes only 40.78mW of power from a 2.5-V power supply.

In this paper, we present a wide dynamic range active pixel sensor (APS) using an external charge pump circuit. The proposed pixel exhibits improved dynamic range through the compensated threshold voltage of a reset MOSFET. We confirmed that the light level which is the saturated output voltage in the proposed APS is about 170,000 lux, which is 36% higher than that of a conventional APS. The proposed APS is fabricated by using 2-poly 4-metal 0.35 &mgr; standard CMOS process. The unit pixel consists of an n+ diffusion / p-substrate photodiode, three NMOSFETs and the charge pump circuit which consists of two NMOSFETs and two capacitors.

With the fast advance of ultra large scale integrated (ULSI) circuit technology, the need for sub-surface imaging technique to locate and characterize sub-surface defects in ULSI circuits has been growing. In this study we advance scanning thermal wave microscopy further so that the absolute phase lag of the thermal waves generated by an electrically heated sub-surface microelectronic structure buried in an ULSI circuit can be measured. The measurement of the absolute phase lag allowed exact locating of the vertical and horizontal position of buried microelectronic structures and evaluation of their soundness nondestructively.

In this paper, the kinetic equation of photo-initiated reaction was set up by measuring the photoinitiator absorbency and the exposure time during the exposure process based on the spectroscopic analysis and reaction kinetics. And an effective and convenient computation model for quantum yields of photoinitiators was established through further analysis of the exposure process. The kinetics curve of photoinitiator 1173 (HMPP) was determined according to this method. The results show that the reaction is consistent with the kinetic model established in this paper. And the quantum yield is 2.4% at the main absorption peak (247nm).

Metamaterials have arisen in an attempt to engineer the electromagnetic properties of natural substances. It has been acknowledged that the emergence of metamaterials has implications to nearly all branches of science and engineering exploiting the electromagnetic radiation. This paper reviews seminal work of metamaterials from the vision to the realisation of subwavelength elements that contribute to varieties of electric and magnetic responses. Emphasis is given to the significance and opportunity of this new class of material augmenting terahertz technology. Although now there remain major milestones that scientists and engineers need to conquer, the future of this cutting-edge material technology is very bright.