With a visual system that accounts for as much as 30% of the lifted mass, flying insects such as dragonflies and hoverflies invest more in vision than any other animal. Impressive visual performance is subserved by a surprisingly simple visual system. In a typical insect eye, between 2,000 and 30,000 pixels in the image are analyzed by fewer than 200,000 neurons in underlying neural circuits. The combination of sophisticated visual processing with an approachable level of complexity has made the insect visual system a leading model for biomimetic approaches to computer vision. Much neurobiological research has focused on neural circuits used for detection of moving patterns (e.g. optical flow during flight) and moving targets (e.g. prey). Research from several labs has led to great advances in our understanding of the neural mechanisms involved, and has spawned neuromorphic hardware based on key processes identified in neurobiological experiments. Despite its attractions, the highly non-linear nature of several key stages in insect visual processing presents a challenge to understanding. I will describe examples of adaptive elements of neural circuits in the fly visual system which analyze the direction and velocity of wide-field optical flow patterns and the result of experiments that suggest that these non-linearities may contribute to robust responses to natural image motion.

Nanomechanical systems, integrated with nanoelectronic transducers and sensors, are in an early stage of development. Research is focused on the development of radiofrequency mechanical resonators, sensitive electrometers and magnetometers, and potentially quantum-limited energy and motion sensors. This paper will review the current state of our efforts in this area, and will describe research in which the integration of mechanics and electronics will potentially allow the demonstration of macroscopic quantum effects in mechanical systems. We are particularly interested in observing and measuring quantum-limited systems, whose behavior is strongly affected by the measurement system; such systems may provide further insight into the quantum measurement process.

The Australian Commonwealth government recently announced a grant of $4.75 million as part of a $13.5 million program to establish a world class networked IC tele-test facility in Australia. The facility will be based on a state-of-the-art semiconductor tester located at Edith Cowan University in Perth that will operate as a virtual centre spanning Australia. Satellite nodes will be located at the University of Western Australia, Griffith University, Macquarie University, Victoria University and the University of Adelaide. The facility will provide vital equipment to take Australia to the frontier of critically important and expanding fields in microelectronics research and development. The tele-test network will provide state of the art environment for the electronics and microelectronics research and the industry community around Australia to test and prototype Very Large Scale Integrated (VLSI) circuits and other System On a Chip (SOC) devices, prior to moving to the manufacturing stage. Such testing is absolutely essential to ensure that the device performs to specification. This paper presents the current context in which the testing facility is being established, the methodologies behind the integration of design and test strategies and the target shape of the tele-testing Facility.

The microelectronics industry has seen explosive growth during the last thirty years. Extremely large markets for logic and memory devices have driven the development of new materials, and technologies for the fabrication of even more complex devices with features sized now don at the sub micron and nanometer level. Recent interest has arisen in employing these materials, tools and technologies for the fabrication of miniature sensors and actuators and their integration with electronic circuits to produce smart devices and systems. This effort offers the promise of: 1) increasing the performance and manufacturability of both sensors and actuators by exploiting new batch fabrication processes developed including micro stereo lithographic an micro molding techniques; 2) developing novel classes of materials and mechanical structures not possible previously, such as diamond like carbon, silicon carbide and carbon nanotubes, micro-turbines and micro-engines; 3) development of technologies for the system level and wafer level integration of micro components at the nanometer precision, such as self-assembly techniques and robotic manipulation; 4) development of control and communication systems for MEMS devices, such as optical and RF wireless, and power delivery systems, etc. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross-linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composite provide a new avenue for future smart systems. The integration of NEMS (NanoElectroMechanical Systems), MEMS, IDTs (Interdigital Transducers) and required microelectronics and conformal antenna in the multifunctional smart materials and composites results in a smart system suitable for sensing and control of a variety functions in automobile, aerospace, marine and civil structures and food and medical industries. This unique combination of technologies also results in novel conformal sensors that can be remotely sensed by an antenna system with the advantage of no power requirements at the sensor site. This paper provides a brief review of MEMS and NEMS based smart systems for various applications mentioned above. Carbon Nano Tubes (CNT) with their unique structure, have already proven to be valuable in their application as tips for scanning probe microscopy, field emission devices, nanoelectronics, H₂-storage, electromagnetic absorbers, ESD, EMI films and coatings and structural composites. For many of these applications, highly purified and functionalized CNT which are compatible with many host polymers are needed. A novel microwave CVD processing technique to meet these requirements has been developed at Penn State Center for the engineering of Electronic and Acoustic Materials and Devices (CEEAMD). This method enables the production of highly purified carbon nano tubes with variable size (from 5-40 nm) at low cost (per gram) and high yield. Whereas, carbon nano tubes synthesized using the laser ablation or arc discharge evaporation method always include impurity due to catalyst or catalyst support. The Penn State research is based on the use of zeolites over other metal/metal oxides in the microwave field for a high production and uniformity of the product. An extended conventional purification method has been employed to purify our products in order to remove left over impurity. A novel composite structure can be tailored by functionalizing carbon nano tubes and chemically bonding them with the polymer matrix e.g. block or graft copolymer, or even cross- linked copolymer, to impart exceptional structural, electronic and surface properties. Bio- and Mechanical-MEMS devices derived from this hybrid composites will be presented.

MEMS/MST technology was introduced over twenty years ago embellished by visions and promises of new products and applications that would revolutionize our lives. As a result we witnessed the creation of many new companies whose goal was to commercialize the technology. However, a few years later commercialization of the technology turned out to be an agonizingly process, a reaction attributed to the overestimation of the speed of technology transfer. This was further complicated by the fact that MEMS, while an enabling technology, is also a disruptive technology destined to completely replace existing, well proven familiar solutions. The adoption of new technology often requires marked evidence of superiority before displacing an established technology. As a rule of thumb, one needs to see a fivefold advantage in some parameters of importance, such as performance and cost, before there is any likelihood of adoption. Several MEMS devices have emerged that evolved into a significant commercial realization. Several others appear to be on the threshold of commercial success. The characteristics of some of these MEMS devices will be examined along with the major players and a number of issues related to overcoming the roadblocks of commercialization. We will also offer some predictions for the future of this technology.

Modern VLSI design is moving towards a System-on-Chip design paradigm, where chip design involves the integration of separate macrocells from different manufacturers. This paper explores the obstacles to adopting this same methodology for systems incorporating MEMS components. These obstacles include the technology specific nature of most MEMS devices, interference between MEMS sensors, and the limited electronics device density of mixed MEMS/Microelectronics technologies. It is conjectured that one fruitful avenue for further work is the development of MEMS interface circuits which can be incorporated into a single SoC along with other electronics macrocells, and which then connect to discrete MEMS sensor chips.

We discuss the conditions under which electromechanical systems, fabricated on a sub micron scale, require a quantum description. We illustrate the discussion with the example of a mechanical electroscope for which the resonant frequency of a cantilever changes in response to a local charge. We show how such devices may be used as a quantum noise limited apparatus for detection of a single charge or spin with applications to quantum computing.

For an array of N summing comparators, each with the same internal noise, how should the set of thresholds, (theta) _i, be arranged to maximize the information at the output, given the input signal, x, has an arbitrary probability density, P(x)? This problem is easy to solve when there is no internal noise. In this case, the transmitted information is equal to the entropy of the output signal, y. For N comparators there are N+1 possible output states and hence y can take on N+1 values. The transmitted information is maximized when all output states have the same probability of occupation, that is, 1/(N+1). In this paper we address some preliminary considerations relating to the maximization of the transmitted information I = H(y) - H(y|x) when there is finite internal noise.

The nuclear spin quantum computer proposed by Kane1 exploits as a qubit array ³¹P dopants embedded within a silicon matrix. Single-qubit operations are controlled by the application of electrostatic potentials via a set of metallic A gates, situated above the donors, on the silicon surface, that tune the resonance frequency of individual nuclear spins, and a globally applied RF magnetic field that flips spins at resonance. Coupling between qubits is controlled by the application of potentials via a set of J gates, between the donors, that induce an electron-mediated coupling between nuclear spins. We report the results of a study of the electric field and potential profiles arising within the Kane device from typical gate operations. The extent to which a single nuclear spin can be tuned independently of its neighbours, by operation of an associated A-gate, is examined and key design parameters in the Kane architecture are addressed. Implications for current fabrication strategies involving the implantation of ³¹P atoms are discussed. Solution of the Poisson equation has been carried out by simulation using a TCAD modeling package (Integrated Systems Engineering AG).

The Horridge Template model is an empirical motion detection model inspired by insect vision. This model has been successfully implemented in several micro-sensor VLSI chips using grayscale pixels. The template model is based on movement of detected edges rather than the whole object, which consequently facilitates simple tracking techniques. Simple tracking algorithms developed by Nguyen have been successful in tracking coherent movement of objects in a simple environment. An extension of the template model using color templates developed by Chin has also been successful in tracking objects moving in close proximity to each other. This paper introduces a low-cost insect vision prototype based on the use of a color CMOS camera. We implement a further extension to the above algorithms with error checking. Several error-checking schemes are used during template formation and manipulation to reduce noise and randomness. This enables the detection of moving objects in noisy environments, which may be applied to many real life situations.

Mathematical Morphology appears as a theory that can solve some drawbacks of the classical lineal image processing. Linear filters generate a spatial distortion from initial image, what gives as a result that specific algorithms are usually needed for each process with a complexity that can not be implemented in VLSI systems for Real Time Image Processing. Mathematical Morphology is an alternative method to overcome the inherent drawbacks of the linear processing based on the comparison of an initial image with some well known geometric figures. In this paper we present the implementation of a specific processor that computes Mathematical Morphology (MM) basic operations. Using a clock frequency of 250 MHz this processor is able to handle real time 512x512 pixels video images. Mathematical Morphology allows the nonlinear processing of images and it is based on Dilation and Erosion operations using a geometric figure called Structural Elements (SE). More complex image processing can be performed using these basic operations. In this implementation the structural element of 3x3 pixels was chosen. 0.6micrometers HgaAsIV standard cells technology, from Vitesse Semiconductor Corporation, has been used achieving a logic level gate description with the possibility of migration to another technologies.

The Block-Matching motion estimation algorithm (BMA) is the most popular method for motion-compensated coding of image sequence. Among the several possible searching methods to compute this algorithm, the full-search BMA (FBMA) has obtained great interest from the scientific community due to its regularity, optimal solution and low control overhead which simplifies its VLSI realization. On the other hand, its main drawback is the demand of an enormous amount of computation. There are different ways of overcoming this factor, being the use of advanced technologies, such as Gallium Arsenide (GaAs), the one adopted in this article together with different techniques to reduce area overhead. By exploiting GaAs properties, improvements can be obtained in the implementation of feasible systems for real time video compression architectures. Different primitives used in the implementation of processing elements (PE) for a FBMA scheme are presented. As a result, Pes running at 270 MHz have been developed in order to study its functionality and performance. From these results, an implementation for MPEG applications is proposed, leading to an architecture running at 145 MHz with a power dissipation of 3.48 W and an area of 11.5 mm².

Layered Surface Acoustic Wave (SAW) devices that allow the propagation of Love mode acoustic waves will be studied in this paper. In these devices, the substrate allows the propagation of Surface Skimming Bulks Waves (SSBWs). By depositing layers, that the speed of Shear Horizontal (SH) acoustic wave propagation is less than that of the substrate, the propagation mode transforms to Love mode. Love mode devices which will be studied in this paper, have SiO2 and ZnO acoustic guiding layers. As Love mode of propagation has no movement of particles component normal to the active sensor surface, they can be employed for the sensing applications in the liquid media.

The MEMS Virtual Prototyping project aims at building a simulation environment that aids in the design of MicroElectroMechanical devices (MEMS). It embodies Computer-Aided Design (CAD) tools for modeling and simulating the functioning of MEMS in virtual reality and to provide visualizations of their performance as multi-parameter functions as virtual reality visualizations and as plots, both based on analytical calculations. The introduction of CAD packages was a critical step in the widespread development of VLSI devices. Despite the demand, there is a noticeable lack of CAD tools to aid in the development of MEMS devices. The purpose of the project presented in this paper is to overcome the weaknesses of the few MEMS-CAD tools that are available. This project analyzes the fundamental steps towards (a) determining critical parameters for typical classes of MEMS (sensors and actuators) (b) identifying visualizations that are meaningful in the MEMS design process, and (c) a novel graphic user-interface architecture to facilitate task switching in CAD-tools, and reducing screen clutter. This paper also describes the Manufacturing module, it explains Visual Design Optimization and provides an application example.

This paper presents the design of a Graphical User Interface for a MEMS CAD tool that addresses the weaknesses of some existing CAD tools for MEMS design. MEMS design is a complex process where many disciplines, processes, materials and structures come together. Consequently, the MEMS CAD tools available are sophisticated and complex tools. The complexity of these tools often exceeds the effectiveness, resulting in unwieldy user interface designs. This in turn impacts the usability of these software packages. We have developed the Task-oriented User Interface Design architecture to address complex system design issues that are inherent in MEMS CAD tools. With this architecture we are able to reduce visual clutter on the screen without loss of functionality, at the same time allowing quick switching between tasks. The architecture is extensible, making it easy to add more MEMS design facilities to the CAD tool.

As MEMS devices are finding more application areas and new devices are developed, the designs of MEMS are becoming more complex. Without computer aid, designers have to rely on experiment and it becomes time consuming. There are a few commercial MEMS design tools are available currently, however these design tools have their limitations. This paper presents the work towards a user friendly MEMS Virtual Reality MEMS CAD tools that models, simulates, and provides the behavior characteristics and virtual reality visualization of MEMS devices. In this part of the project - the sensor component, we analyze the requirements for modeling MEMS sensors by investigating several types of MEMS, their operating characteristics and their corresponding design parameters. An application example serves to illustrate the analysis and applicability of the models in the sensors component, and to investigate its interaction with other components such as user interface, VR animation, and manufacturing module.

The pleasing and intuitive visualization images of Micro-Electro-Mechanical Systems (MEMS) assist microtechnology researchers and designers extract significant features and results quickly and easily. The detailed visualization through different points of view may reduce a MEMS design trial and error phase for system elements dimension and placement. The work presented in this paper is part of a research project for developing MEMS Virtual Reality prototyping software. The objective of the project is to build a simulation environment that aids in the MEMS design. Scientific visualization design tools make it easier for MEMS designers to view their results functioning in 3D Virtual Reality on a computer screen before shaping a physical prototype. This paper discusses the issues that are relevant in the development of producing the MEMS VR images and their animations. The images for applying visualization and Virtual Reality to demonstrate a sensor and an actuator are shown.

The design stage of the development of a MEMS device is crucial if its fabrication is to be right the first time. Computer-aided design (CAD) helps to accelerate this process and provides a cost-effective method in the prediction and optimization of device characteristics. This paper describes this design process, focusing on the conceptual design phase in the development of microactuators as part of the actuator component of a Virtual Reality-prototyping CAD tool. To create the functions and database required for this tool, the effects of parameters such as temperature, pressure, strain, acceleration etc., on the microactuator have to be evaluated. To achieve this, a comprehensive analysis of the most relevant parameters affecting the different types of microactuators based on their force-producing principle is required. This is a huge and lengthy task. It includes the estimation of mechanical performance of the device with variation in its geometrical structure and the optimization of the variations with respect to their static and dynamic performance, for example linearity and resonant frequency. It aids in the analysis of constraints in the geometrical design for robustness in its manufacture. In this paper we analyze the requirements, the functions and database entries, via an application case example for a membrane micropump. Its structure is studied in order to demonstrate the feasibility of using this device as a pump that is able to move air from one chamber to another. In this example we look at the underlying models that warrant a desired performance and whose calculations results in the geometries and operational parameters, such as the flow of air or liquid, the deflection of the membrane, etc. These results serve as input to the Virtual Reality Visualizations module and displayed with time and size scaled animations.

There is increasing interest among research groups around the world in the terahertz portion of the electromagnetic spectrum. T-ray systems, driven by ultrafast THz pulses, offer a number of unique advantages over other techniques and are under investigation for a wide range of applications. Biomedical diagnostics is an area of particular emphasis. The sub-millimetre spectroscopic measurements obtained from T-ray systems contain a wealth of information about the sample under test. A number of hurdles, however, hinder the application of T-ray technology. One of the major hurdles to be overcome is the slow acquisition speed of modern THz systems. The chirped probe pulse technique offers a significant improvement in this context. We present results demonstrating the terahertz responses of biological samples measured using a chirped probe pulse, and discuss the problem of data processing and extracting sample characteristics. We show that different types of tissue can be classified based on their terahertz response measured with the chirped probe pulse technique. We consider chicken and beef samples and differentiate between bone and normal tissue. We demonstrate the performance of linear filter models for feature extraction and show that these models are significantly more accurate than a number of intuitive features.

In this paper, design concepts of reconfigurable and electronically steered antennas based on a new fractal antenna and FR-MEMS devices are presented. The input characteristics of the Hilbert curve fractal antenna can be made frequency agile by incorporating RF-MEMS switches along its length. In addition, due to the large number of connected segments in this antenna geometry, reconfigurable radiation characteristics can be obtained by adding just few additional line segments to interconnect these through semiconductor or RF-MEMS switches. The beam peak direction can be shifted by 63 degree(s) and the beam width can be changed by up to 25 degree(s) by this approach. An electronically steered antenna with micromachined phase shifters using tunable ferroelectric barium strontium titanate thin film is also discussed. These MEMS based antenna systems find applications in communications satellites and electronically scanned arrays for space-based radars.

Characterizing the optical and dielectric properties of thin films in the GHz to THz range is critical for the development of new technologies in integrated circuitry, photonics systems and micro-opto-electro-mechanical systems (MOEMS). Terahertz differential time-domain spectroscopy (DTDS) is a new technique that uses pulsed terahertz (THz) radiation to detect phase changes of less than 0.6 femtoseconds (fs) and absorption changes corresponding to several molecular monolayers. This paper shows how DTDS can be combined with double modulation in the pump-probe system to improve sensitivity by an order of magnitude. The technique is experimentally verified using 1 μm thick samples of silicon dioxide on silicon.

T-ray imaging and spectroscopy both exploit the terahertz (THz) region of the spectrum. This gives rise to very promising industrial and biomedical applications, where non-invasive and sensitive identification of a substance is achievable, through a material's distinct absorption features in the THz band. Present T-ray systems are limited by low output power, and the race is now on to find more efficient THz emitters. We discuss the feasibility of a novel high-power gallium nitride emitter for terahertz generation. This paper details the advantages of such an emitter, primarily by virtue of its high-voltage capability, and evaluates the benefits of sapphire and silicon carbide substrates. The far-infrared transmission spectra for thin samples of GaN, sapphire and SiC are reported. A high-power THz emitter, that operates at room temperature and is potentially low-cost will open up a host of new possibilities and applications. The central result in this paper demonstrates that sapphire is the better choice over SiC, for the GaN supporting substrate, as we show that it has superior THz transmission characteristics.

Today's increasing data rates in digital communication circuits are demanding higher speeds in the interchip communication. This throughput can be achieved using high rate serial links. Good noise inmunity can be obtained by means of differential strategies and an important power reduction can be obtained by using current mode operation. In this paper, a innovative differential current mode transmitter/receiver pair is presented which combines both, good noise inmunity with low power dissipation.

This paper describes an ATM transceiver implementation with add/drop function over SDH (Synchronous Digital Hierarchy) able to handle STM-16c (OC-48c) signals. The design has been developed using Vitesse HGaAs-IV technology using DCFL (Direct Coupled FET Logic) standard cells and obtaining, in this way, a logic gate level description which could be easily exportable to any technology.

Though the frequency measurement technique is well established, converting frequency to a digital world for real time systems is not an easy task. The task is further complicated by the absence of any standard peripheral integrated circuit chip for this application. The existing techniques of frequency measurement like direct frequency measurement and period measurement are not accurate at low and high frequencies respectively. This talk will elaborate the effort involved to realize a successful Frequency to Digital Converter (FDC) as an Application Specific Integrated Circuit (ASIC). The chip adopts an innovative frequency measurement technique called the hybrid technique. The hybrid technique has the advantage of both the direct frequency and period measurement techniques and is found to be very accurate at both low and high frequencies. The chip was designed and fabricated with stringent specifications to meet military applications. Extensive software simulations were done to ensure the proper functioning of the chip. The chip was then tested extensively over all frequencies and was found to operate successfully meeting all the specifications.

The first main result of this paper is the development of a low power threshold logic gate based on a capacitive input, charge recycling differential sense amplifier latch. The gate is shown to have very low power dissipation and high operating speed, as well as robustness under process, temperature and supply voltage variations. The second main result is the development of a novel, low depth, carry look ahead addition scheme. One such adder is also designed using the proposed gate.

The inertial navigation system uses both gyroscopes and accelerometers to measure the state of motion of a target or a vehicle by sensing the changes in that state caused by accelerations. The required features in many of these applications are high precision, wide dynamic range and wide frequency range. In this paper, recent advances made on Wireless MEMS-IDT based accelerometers and gyroscopes are presented. The concept and design principles underlying a MEMS-IDT (Interdigital Transducer) based accelerometer and gyroscope are based on using surface acoustic waves (SAW) and polysilicon seismic mass for acceleration and proff mass for gyro. This unique concept is a departure from the conventional comb driven MEMS accelerometer design. By designing the seismic mass of the accelerometer to float just above a high frequency Rayleigh Surface Acoustic Wave Sensor (SAWS), we are able to realize the accuracy and versatility required for the measurement of accelerations from 10^-6g to 100g. The gyro design is based on the combination of Surface Acoustic Wave Resonator (SAWR) and Surface Acoustic Wave Sensor, which operates at the Rayleigh mode. They possess typical advantages of MEMS sensors including the additional benefits of robustness, excellent sensitivity (about 1 deg./hr.), surface conformability and durability. The transmitter IDT creates SAW (Surface Acoustic Wave) that propagates back and forth between the reflectors and forms a standing wave pattern within the cavity space between the IDTs. The particles at the anti- nodes of standing wave pattern experience large amplitude of vibration perpendicular to the plane of the substrate, which serves as the reference vibrating motion for this gyroscope. A number of metallic (proof) masses are strategically positioned at the anti-node locations so that the effect of the Coriolis force can be used to sense the gyroscopic motion. Another unique feature of the device is that because the SAW device operates at RF frequencies, one could easily connect the IDT device to a microstrip antenna and read the acceleration and gyro rate remotely by wireless transmission and reception using the Bluetooth technology. This concept is proposed in this paper.

In this paper, the implementation and results obtained for a Gallium Arsenide (GaAs) multiplierless filter bank with applications on Two Dimensional Discrete Wavelet Transform (2D-DWT) are presented. Among the benefits offered by this architecture, its configurable characteristics, which allow affording input images with different sizes, as well as the ability to compute up to 10 levels of sub-band decomposition, are outlined. Different types of filters have been studied in order to select the one that best matches the requested applications. This election is based on a compromise among compactness of relevant image information in the LL sub-band, compression algorithms and VLSI simplicity. As a result, a filter running at 250 MHz with 3.2W of power dissipation is obtained, allowing CCIR applications.

As the working range goes up, micro-accelerometer confronts big challenges at sensitivity and time stability. In this paper, the scheme of design and test of a large operating range accelerometer with low drift and low noise is presented. The focus is on the structure design, process consideration and interface circuit optimization. Computer simulations of sensor structure and servo system are also introduced. The accelerometer is produced and tested. Gravity field and centrifugal measurement shows that its sensing range reaches 60g, and the full-scale nonlinearity is less than 1x10^-4. The noise level is monitored to be less than 3mg/(rootHz. As the time stability is concerned, it takes a few seconds to give out a stable output, the drift less than 0.01g, and the long-term drift is as low as 3mg.

A novel Micro-Electro-Mechanical System (MEMS) filter is proposed for direct acoustic signal processing. Compared with contemporary post-signal processing techniques with digital signal processors (DSP), our proposed MEMS filters generate the transformed information without the DSP incorporation. Owing to their excellent characteristics, the MEMS filter will be an effective device for acoustic signal processing. Coupling with the phase and the amplitude shift near resonant frequency, two and above micromachined structures are used to comprise the proposed MEMS filter. In the study, we designed and simulated the MEMS filters, consisting of different resonating structures, to process acoustic signals. With the simulation results, the optimized parameters of the structure can be followed by the MEMS Q factor, a new characteristic parameter for MEMS filter, versus the damping factor chart. Under the fine-tuning of the two parameters, all the desired MEMS filters can be easily realized.

While the micro bimorph structures are fabricated with enough initial curvatures or so-called geometrical imperfections, structural instability may occur to result in snap-through behaviors and exhibit large deflection strokes. The bimorph structures with various initial deflections ratios and various heating area ratios are simulated and fabricated to predict the stable and unstable regions of the curved bimorph structures with clamped boundary condition. Four major types of load-deflection curves are described and discussed. Testing results and some observations are reported.

This paper describes the characterization of a CMOS humidity sensor using three Dupont polyimides, PI2555, PI2610, and PI2723 as sensing films. The sensing principle of the sensor is the dielectric constant change of deposited sensing films due to absorption/adsorption of water. The humidity sensing film is deposited by a post-processing step after the standard CMOS fabrication. The on-chip calibration circuit is based on a switched-capacitor front-end, featuring high linearity, insensitivity to temperature, as well as low power consumption. The measured results show that the coating film thickness incluences the sensor response speed, but has no influence on the sensor transfer function, thanks to the on-chip calibration circuit. Sensor coated with PI2555 has better performance then other two regarding to sensitivity, response speed, and stability.

Visual detection and processing of motion in insects is thought to occur based on an elementary delay-and-correlate operation at an early stage in the visual pathway. The correlational elementary motion detector (EMD) indicates the presence of moving stimuli on the retina and is directionally sensitive, but it is a complex spatiotemporal filter and does not inherently encode important motion parameters such as velocity. However, additional processing, in combination with natural visual stimuli, may allow computation of useful motion parameters. One such feature is adaptation in response to motion, until recently thought to occur by modification of the delay time constant, but now shown to arise due mainly to adjustment of contrast gain. This adaptation renders EMD output less dependent on scene contrast and enables it to carry some velocity information. We describe an ongoing effort to characterize this system in engineering terms, and to implement an analog VLSI model of it. Building blocks for a correlational EMD, and a mechanism for computing and implementing adjustment of contrast gain are described. This circuitry is intended as front-end processing for classes of higher-level visual motion computation also performed by insects, including estimation of egomotion by optical flow, and detection of moving targets.

The sensor processor circuit has been developed for hand-held devices used in industrial and environmental applications, such as on-line process monitoring. Thereby devices with SAW sensors or MEMS resonators will benefit from this processor especially. Up to 8 sensors can be connected to the circuit as multisensors or sensor arrays. Two sensor processors SP1 and SP2 for different applications are presented in this paper. The SP-1 chip has a PCMCIA interface which can be used for the program and data transfer. SAW sensors which are working in the frequency range from 80 MHz to 160 MHz can be connected to the processor directly. It is possible to use the new SP-2 chip fabricated in a 0.5(mu) CMOS process for SAW devices with a maximum frequency of 600 MHz. An on-chip analog-digital-converter (ADC) and 6 PWM modules support the development of high-miniaturized intelligent sensor systems We have developed a multi-SAW sensor system with this ASIC that manages the requirements on control as well as signal generation and storage and provides an interface to the PC and electronic devices on the board. Its low power consumption and its PCMCIA plug fulfil the requirements of small size and mobility. For this application sensors have been developed to detect hazardous gases in ambient air. Sensors with differently modified copper-phthalocyanine films are capable of detecting NO₂ and O₃, whereas those with a hyperbranched polyester film respond to NH₃.

We have been developing a silicon-based integrated optic pressure sensor using an intermodal interference between the fundamental TM-like and TE-like modes. The sensor has a micromachined diaphragm with a sensing waveguide as a pressure-sensitive structure. The sensor is theoretically known to have a strong dependence of sensitivity on the sensing waveguide on the diaphragm. According to the theoretical prediction for the sensor based on the elasto-optic effect, the waveguide should be placed along the diaphragm edge to maximize sensitivity. To date, such dependence has not been experimentally examined in detail. In this study, two sensors with 20 or more waveguides placed at 0.1mm intervals on the diaphragm were fabricated to determine the relationship between sensitivity and waveguide position. The diaphragm dimensions were (1) 2.0mmX10mmX35micrometers and (2) 3.0mmX15mmX64micrometers . The ratio between width and length of each diaphragm was 1:5. The maximum sensitivity of 100 mrad/kPa was obtained for the waveguide nearest to the diaphragm edge with a wavelength of 633nm. In addition, the measured sensitivities were very similar for the corresponding waveguide positions in the two sensors since a scaling factor, which is defined as the cube of the either side length divided by the square of the thickness, was set as a constant.

The two-photon storage technology is discussed for the ultra-high-density three-dimensional optical data storage in this paper. We present the miniatured design of the optical head for the two-photon storage. Binary optical technology is used to obtain the desired reading and writing beams in an integrated optical head. Arrayed optical head system is designed to increase the data transmission speed. This design can reduce the weight and simplify the structure of the optical head system, and is helpful to make the two- photon storage technology commercialized.

In this paper we propose an on-pixel Analog-to-Digital converter based on pulse frequency modulation (PFM) scheme. This PFM based converter presents a very viable solution for pixel level based ADC. It uses a very simple and robust circuit that can be implemented in a compact area resulting in a 23% fill-factor. The low-light performance of the PFM converter is improved by using a wider counting period. By modifying the counting period, it is possible to change the saturation level of the ADC and hence improve the dynamic range of the sensor. Image lag is eliminated in the PFM On-pixel ADC since a reset of the photodetector is performed after the conversion period. In addition, the PFM on-pixel ADC has a very important advantage: it is insensitive to variations of the supply and reference voltages. The pixel based ADC has been designed and fabricated using CMOS 0.25micrometers technology.

Assessment of the ability of the autonomic nervous system (ANS) to regulate blood pressure (BP). This is of particular importance for elderly people, for whom the project was designed. We measure a patient's BP noninvasively under various conditions: deep respiration, passive tilt, etc. The variability of the heart rate in the lower frequency band (LF) (0.04 - 0.15 Hz) is known to have sympathetic- and parasympathetic origin, while in the higher (HF) (0.15 - 0.4 Hz) it is vagally mediated. We do a Time-Frequency analysis for the two frequency bands (Wigner) and eliminate the 'cross-terms' with a novel method due to Qian and Chen. We obtain a clear resolution of the activity in LF and HF over time. Research is ongoing aiming at identifying unambiguously the sympathetic and vagal activity.

The role of interference and entanglement in quantum neural processing is discussed. It is argued that on contrast to the quantum computing the problem of the use of exponential resources as the payment for the absence of entanglement does not exist for quantum neural processing. This is because of corresponding systems, as any modern classical artificial neural system, do not realize functions precisely, but approximate them by training on small sets of examples. It can permit to implement quantum neural systems optically, because in this case there is no need in exponential resources of optical devices (beam-splitters etc.). On the other hand, the role of entanglement in quantum neural processing is still very important, because it actually associates qubit states: this is necessary feature of quantum neural memory models.

Redundancy is where multiple agents perform one task. On the other hand, pleiotropy is the inverse of redundancy- that is, where one agent multitasks. In real systems it is usual to find a mixture of both pleiotropic and redundant agents. In engineered systems we may see this in communication networks, computer systems, smart structures, nano-self-assembled systems etc. In biological systems, we can also observe the interplay of pleiotropy and redundancy from neural networks through to DNA coding. The open question is how to design a given complex system with the correct trade-off between redundancy and pleiotropy, in order to confer maximum robustness for lowest cost. Here we propose an evolutionary computational approach for exploring this trade-off in a toy model cellular automation, dubbed Real Life.

A new current controlled very high value resistor is presented and discussed. The new very high value floating resistor is built using a new topology that converts a grounded resistor or conductance to floating one. The output conductance of two matched transistors in the saturation region of operation is utilized for the resistor implementation. Hence, resistance value in the range of G(Omega) is achievable through a reasonable bias current in the range of 500 nA with small silicon area. The linearity of the new resistor is less than +/- 1 percent (THD) for a 2 V_pp input signal in a 5 volt 1.2micrometers CMOS technology. The resistor is useful in the design of a very low frequency bandpass filter for artificial insect vision chip and pacemaker applications.