Since the discovery of piezoresistivity in silicon in the mid 1950s, silicon-based pressure sensors have been widely produced. Micromachining technology has greatly benefited from the success of the integrated circuits industry, borrowing materials, processes, and toolsets. Because of this, microelectromechanical systems (MEMS) are now poised to capture large segments of existing sensor markets and to catalyze the development of new markets. Given the emerging importance of MEMS, it is instructive to review the history of micromachined pressure sensors, and to examine new developments in the field. Pressure sensors will be the focus of this paper, starting from metal diaphragm sensors with bonded silicon strain gauges, and moving to present developments of surface micromachined, optical, resonant, and smart pressure sensors. Considerations for diaphragm design will be discussed in detail, as well as additional considerations for capacitive and piezoresistive devices.

Knowledge of ice conditions on important aircraft lift and control surfaces is critical for safe operation. These conditions can be determined with conventional ice-detection sensors, but these sensors are often expensive, require elaborate installation procedures, and interrupt the airflow. A micromachined, silicon-based, flush-mounted sensor which generates no internal heat has been designed, batch fabricated, packaged, and tested. The sensor is capable of distinguishing between an ice-covered and a clean surface. It employs a bulk micromachined wafer with a 7 micrometers -thick, boron-doped, silicon diaphragm which serves as one plate of a parallel-plate capacitor. This is bonded to a second silicon wafer which contains the fixed electrodes-- one to drive the diaphragm by application of a voltage, the other to measure the deflection by a change in capacitance. The diaphragm sizes ranged from 1 X 1 mm to 3 X 3 mm, and the gap between parallel-plate capacitors is 2 micrometers . A 200 d.c. was applied to the driving electrode which caused the capacitance to increase approximately 0.6 pf--from a nominal capacitance of 0.6 pf--when the surface was ice free. After the sensor was cooled below the freezing point of water, the same voltage range was applied to the drive electrode. The capacitance increased by the same amount. When a drop of water was placed over the diaphragm and allowed to freeze, no change in capacitance was measured, confirming that the diaphragm was locked to the ice layer. Since the sensor uses capacitive actuation, it uses very little power and is an ideal candidate for inclusion in a wireless sensing system.

This paper describes the design and implementation of a surface micromachined accelerometer for measuring very high levels of acceleration (up to 50,000 G). Both the mechanical and electronic portions of the sensor were integrated on a single substrate using a process developed at Sandia National Laboratories. In this process, the mechanical components of the sensor were first fabricated at the bottom of a trench etched into the wafer substrate. The trench was then filled with oxide and sealed to protect the mechanical components during subsequent microelectronics processing. The wafer surface was then planarized in preparation for CMOS processing using Chemical Mechanical Polishing. Next, the CMOS electronics were fabricated on areas of the wafer adjacent to the embedded structures. Finally, the mechanical structures were released and the sensor tested. The mechanical structure of the sensor consisted to two polysilicon plate masses suspended by multiple springs (cantilevered beam structures) over corresponding polysilicon plates fixed to the substrate to form two parallel plate capacitors. The first polysilicon plate mass was suspended using compliant springs (cantilever beams) and acted as a variable capacitor during sensor acceleration. The second polysilicon plate mass was suspended using very stiff springs and acted as a fixed capacitor during acceleration. Acceleration was measured by comparing the capacitance of the variable capacitor (compliant suspension) with the fixed capacitance (stiff suspension).

In the previous paper, preliminary research results on powder particle assemblage technique using a microprobe was reported. It was shown that the technique makes it possible to manipulate powder particles one by one, etch microscopically and weld the powder particle into a substrate or other powder particles. In this work, the welding mechanism of this method and metallurgical properties of welded parts were investigated, and micro- actuators were fabricated by means of powder particle assemblage technique using the microprobe. The results indicated the potentiality of this technique for application to assemblage of micro-machine and micro-devices.

A low-temperature (< 300 degree(s)C) polymer micromachining process has been developed, whereby the sensor can be fabricated directly on substrates containing complete electronic circuits. This approach is strong since any IC process can be selected with no regard to the sensor process. Condenser microphones have been fabricated with a sensitivity of 8.1 mV/Pa, flat frequency response between 100 Hz and 15 kHz, and an equivalent noise level of 24 dBA SPL. Differential pressure sensors have been made with a nominal sensitivity (Delta) C/C of 17%/bar for a pressure range 1 bar. Furthermore, uni-axial accelerometers with a nominal sensitivity of 0.43%/g have been implemented. From these results it may be concluded that IC-compatible capacitive sensors with good performances can be achieved with this technology, and it is suggested that the use of polymer processing on silicon therefore may become an important issue in smart sensors of the future.

One of the critical issues in embedding smart patches (i.e., integrated sensors, actuators, electronics, and control) in smart structures is power delivery and communications to and from the patches. In this paper, design and experimentation of microstrip antenna elements and arrays integrated with piezoelectric substrates for novel wireless communication in smart structures are presented. Furthermore, we will discuss the general concept, analysis and design of microstrip antennas in a multilayered dielectric-piezoelectric environment, experimental demonstration of remote sensing and actuation mechanism, and address important considerations and potential practical applications.

Recently there has been considerable interest toward designing and developing `smart skins' for aircraft. The smart skin is a composite layer which may contain conformal radar, conformal microstrip or spiral antennas for electromagnetic applications. These embedded antennas will given rise to very low radar cross section or can be completely `hidden' to tracking radar. In addition, they can be used to detect, monitor or even jam other unwanted electromagnetic field signatures. The conformal electronically steerable antenna may find useful as a communication link between sensors, actuators and controllers in future `smart' aircraft. The smart skin structure containing the antenna should not only compensate for unwanted structural vibration but also maintain the electromagnetic beam steering and power density (beam shaping). This paper is designed to address some technical advances made in the design and development of thin, wideband, conformal antenna architecture that is structurally integratable and both structurally and electronically tunable using multifunctional piezo, ferroelectric and chiral materials.

Recent studies have shown that reflector surface adaptation can achieve performance characteristics on the order of some phase array antennas without the complexity and cost. The work presented in this study develops the experimental groundwork for a class of antennas capable of variable directivity (beam steering) and power density (beam shaping) The actuation for these antennas is employed by bonding polyvinylidene fluoride (PVDF) film to a metalized mylar substrate. A voltage drop across the material will cause the material to expand or contract. This movement causes a moment to be developed in the structure which causes structural bending. Several studies of flexible structures with PVDF films have shown that cylindrical antennas can achieve significant deflections and thereby offer beneficial changes to radiation patterns emanating from aperture antennas. In this study, relatively large curved actuators are modeled and a deflection vs. force relationship is developed. This relationship is then simulated and compared to experimental results. A final simulation of the far field radiation patterns from a given set of deflections is then presented.

High-performance multi-sensing devices represent a good compromise between the integrated and hybrid microelectronic because their limited production and high-tech design. New low-cost electronic interface to process signals generated by different types of physical sensors are a prerequisite in order to guarantee efficient and reliable components able to work even in the most difficult industrial environment. The purpose of this work is to define design criteria and accuracy evaluation procedures by means of a dedicated theoretical framework. Extended experimental tests confirmed these results in the particular case of tactile sensors for robotics showing the excellent ratio between performance and costs of the system. Specific applications of this work can be found also for many other types of sensing elements typical of high-performance industrial devices.

This paper describes the design of a clock generation circuitry to be used as part of an affordable gigabit module head mounted display. A self-calibrated tapped delay line is used to generate different clock signals, which are then passed through logical function to produce an integral- multiple of an input clock. The system is fabricated on 0.8 micrometers CMOS triple layer using MOSIS CMOS process. All processes technology can operate at 3.3 V or 5.0 V. Experimental results show a realization of 4 times clock multiplier circuit with an output range of up to 370 MHz with almost zero-clock skew. The proposed clock multiplier circuitry is simple, temperature independent, uses a very small number of transistors and hence requires less area and power dissipation than earlier realizations.

Gray scale deformable grating spatial light modulators have been fabricated using surface MEMS processes and are being tested prior to integration with addressing silicon backplanes. Modulation rates in excess of 100 kHz have been observed with test devices as have modulation depths nearing 40 dB.

Microelectromechanical systems or MEMS have evolved into multiple component mechanisms. MEMS may consist of mechanical elements such as flexible beams and optical components, these elements may require precision structural pointing or manipulation. Vibrations from MEMS elements and environmental disturbances may interfere with precision motion requirements. Specific MEMS applications examined that may require microactuation control include scanning probe microscopes and microgrippers. A device merging smart material and microelectromechanical system concepts is presented as a response to MEMS active control needs. The device, approximately 2000 X 200 X 800 micrometers is a strain amplification mechanism composed of electroplated nickel. The device amplifiers stroke of piezoelectric material and is constructed using the LIGA technique. Experimental results are presented along with finite element analysis of the mechanical microamplifier indicating a viable design solution exits for solid-state microactuators.

The authors propose the use of a thin plastic film as a diaphragm for a silicon micropump. The plastic diaphragm allows large elastic deflection comprising a microsystem with corrosion resistant and low coefficient of friction. All aspects exploited through the development of a micropump with further advantages of eliminating several processing steps when compared with microdevices employing silicon as the thin vibration element. Low viscosity epoxy resigns and 100 micrometers polyethylene sticky tapes were used to overcome the relatively poor adhesion characteristics of plastics to silicon. The polyethylene sticky tape provides the weak bond onto a silicon wafer having microstructures fabricated by silicon bulk micromachining process. Type EPOFI 40200029 (Struers) low viscosity epoxy resin was used to obtain excellent sealing and high bonding strength between the silicon substrate and the plastic diaphragm. Low viscosity epoxy led to the deep penetration of the epoxy resulting in good sealing characteristics. The diaphragm and silicon micropump developed were tested with an external pneumatic actuator and showed excellent performance at pressures in the range of 0 - 30 psi.

Piezoelectric thin films have been integrated with silicon microfabrication methods in the formation of both sensors and actuators (commonly called MEMS). This work describes several applications of merged PZT thin film technology, solid-state micromachining, and silicon-based integrated circuit fabrication methods in the formation of acoustic emission microsensors, cantilever microbeam accelerometers, diaphragm micropumps, and cantilever microvalves. When combined with CMOS-based integrated circuits, these sensors and actuators form smart microelectromechanical systems with potentially low-cost and high performance.

As the Wright Lab Air Force military contrast `Smart Skin Structures Technology Demonstration' (S<sup>3</sup>TD) Contract No. F33615-C-93-3200 draws toward conclusion, pertinent features of the program finite element modeling are presented. Analysis was performed to predict the structural performance of a complex multilayered composite panel that will be tested structurally (and electrically) for the final program deliverable. Application of finite element modeling to predict component load path and strain distribution in sandwich panel construction has been reported elsewhere in the literature for more standard applications. However, the unauthordox sandwich configuration lay-up posed by the quite revolutionary S<sup>3</sup>TD CLAS aircraft fuselage panel demonstration article merits further discussion. Difficulties with material selection, the stumbling block for many programs, are further exacerbated by conflicting material properties required to support simultaneous electrical and structural performance roles. The structural analysis challenge derives from S<sup>3</sup>TD's unique program goal, namely, to investigate load bearing antennas structural configurations, rather than conventional structurally inefficient `bolt in' installations, that have been the modus operandi for tactical aircraft antenna installations to date. Discussed below is a cost saving strategy where use of linear finite element analysis has been employed in the prediction of key structural parameters, and validated with risk reduction sub panel measurements, before proceeding to the final fabrication of a full scale 36 by 36 inch CLAS panel demonstration article.

Further proof-of-concept development for structurally integrating communication antennas in the vertical tail of a military aircraft at Northrop Grumman is presented. Bread board testing on a full scale dual tail aircraft mock-up of a structurally integrated multifunction tail tip antenna, in the VHF-FM, VHF-AM, and UHF-AM frequency regimes, has confirmed earlier simulation results, where it was suggested that smart skin installation electrical performance gain and radiation characteristics might compare favorable to conventional dorsal deck mounted blade installations. Scale model, and eventually full scale ground mock-up testing encouraged further development leading to fabrication of a preliminary flight test of a smart skin tip demonstration article. A low cost flight test program in the VHF SINCGARS band (30 to 88 MHz) has illustrated that structural integration, fabrication and manufacturing issues can be addressed for full feasibility with minimum penalties despite the hostile vibro-acoustic, moisture and electromagnetic environment. Salient features of the engineering technical design effort and recommendations for future concept development are discussed.

The Structures Division of the Air Force's Wright Laboratory is sponsoring the development and demonstration of a new high pay-off technology termed CLAS--Conformal Load Bearing Antenna Structures. Northrop Grumman Corporation and TRW/ASD are developing the technology under the `Smart-Skin Structure Technology Demonstration (S<sup>3</sup>D)' program, contract, No. F33615-93-C-3200. The program goal is to design, develop, fabricate, and test a CLAS component and lay the foundation for future work where potential benefits from structurally integrated antennas may be realized. Key issues will focus but are not limited to the design, structures, and manufacturing aspects of antenna embedment into load bearing aircraft structures. Results from Phase 1 of the program have been previously reported, where initial pay-offs in reducing overall airframe acquisition and support cost, weight, signature, and drag were quantitatively and qualitatively identified. A full-sized CLAS component, featuring a broadband multi-arm spiral embedded in sandwich stiffened structure, will be fabricated and tested for static strength, durability, and damage tolerance. Basic electrical performance, (e.g., radiation patterns, gain, and impedance) will also be verified; however, extensive electrical validation will be the subject of further work. Key aspects of the work and progress to date are detailed below. Also covered are future projections of CLAS technology expansion beyond tactical aircraft into other military products highlighting ships, army vehicles, and `spin-off' commercial applications to civil aircraft and the automotive industry.

Surface acoustic wave (SAW) devices have been studied for the last twenty years as highly sensitive yet relatively inexpensive microsensors for applications ranging from gas and biological sensing to thin film and surface characterization. This wide range of applications is due to SAW microsensors high sensitivity to several physical parameters including mass, conductivity, permittivity, stress, temperature and electric fields. Their low cost results from the use of standard batch microelectronic fabrication techniques for their manufacture. In this work several SAW sensing applications are described. These include: gas detection; thin film polymer characterization; dew-point measurements; surface energy measurements; and as a method to measure surface cleanliness. Experimental results are presented along with comparisons to other measurement techniques.

Smart MEMS (MicroElectroMechanical Systems) in the form of integrated sensors and actuators offer significant potential for many rotorcraft applications. Sensing of flex beam deflection and acceleration, ice formation and deicing are major candidate areas where smart conformal MEMS based sensors can be exploited by the rotorcraft community. The major technical barrier of the present day smart structures technology is the need for wired communication between sensors and actuators in the rotating system and controllers, data storage units,a nd cockpit avionics. Many proposed sensors and actuators are commonly distributed either along the blade length or, in the active flap devices, out near the 75% blade radial station. Also they are not conformed to the airfoil shape of the rotor blades. The communication between rotating and fixed systems is typically accomplished using complex slip ring assemblies transferring electronic information down through the rotor shaft. Although advances have been made in wired communication, these complex assemblies are essentially similar to test hardware and present numerous reliability and maintainability limitations when implemented on a production scale. Considering these limitations, development of a wireless means of communication through a new generation of conformal sensors with built-in antenna, akin to telemetry, could have a dramatic beneficial payoff for rotorcraft applications.

The integration of MEMS, SAW devices and required microelectronics is presented in this paper. This unique combination of technologies results in a novel sensor that can be remotely sensed by a microwave system with the advantage of no power requirements or very low power requirements. Such a device is readily compatible with existing antenna technologies as the SAW device operates at 1 GHz. The microaccelerometer presented is simple in construction and easy to manufacture with existing silicon micromachining technology. Depending on the application certain design parameters can be modified to achieve the desired sensitivity. Similar modifications in the microelectronics can also be envisioned. A fabrication method to produce such a device is also presented. The relatively small size of the sensor makes it an ideal conformal sensor. The accelerometer finds application as air bag deployment sensors, vibration sensors for noise control, deflection and strain sensors, inertial and dimensional positioning systems, ABS/traction control, smart suspension, active roll stabilization and four wheel steering.

Successful direct integration of a mechanical structure fabricated by LIGA on a Si chip containing CMOS circuitry has been achieved in this work. A 1D cantilever accelerometer is chosen as a vehicle to demonstrate this integration process. The capacitive sensor element employs one electrode formed in the Si substrate during the integrated circuit fabrication. The other electrode is fabricated using the LIGA technique with sacrificial layer etching. Details of the fabrication process to achieve this integration are given. Need for careful control of stress in the deposited layers and achieving appropriate contrast in the X-ray mask are delineated.

One of the principal applications of monolithically integrated micromechanical/microelectronic systems has been accelerometers for automotive applications. As integrated MEMS/CMOS technologies such as those developed by U.C. Berkeley, Analog Devices, and Sandia National Laboratories mature, additional systems for more sensitive inertial measurements will enter the commercial marketplace. In this paper, we will examine the key technology design rules which impact the performance and cost of inertial measurement devices manufactured in integrated MEMS/CMOS technologies. These design parameters include: (1) Minimum MEMS feature size, (2) Minimum CMOS feature size, (3) Maximum MEMS linear dimension, (4) Number of mechanical MEMS layers, and (5) MEMS/CMOS spacing. In particular, the embedded approach to integration developed at Sandia will be examined in the context of these technology features. Presently, this technology offers MEMS feature sizes as small as 1 micrometers , CMOS critical dimensions of 1.25 micrometers , MEMS linear dimensions of 1000 micrometers , a single mechanical level of polysilicon, and a 100 micrometers space between MEMS and CMOS.

Integrated Force Arrays (IFAs) are thin film linear actuators which operate with substantial displacement and force. The methods of attachment of these devices to external systems are under development. Our current methods to incorporate IFAs in an scanning ultrasound imaging systems as well as a new material and method for attachment will be described.

Even though the frequency measurement technique is well established, converting frequency to a digital word for real time systems is not an easy task. The task is further complicated by the absence of any standard peripheral integrated chip for this application. In this paper, an Application Specific Integrated Circuit has been realized for a successful frequency to digital conversion. The chip adopts an innovative frequency measurement technique called the `hybrid technique'. The chip was designed with very stringent specifications to meet military and civilian applications. Extensive software simulations were done to ensure the proper functioning of the chip.

Micromachined hotplates, membranes, filaments, and cantilevers have all been used as platforms for thermal sensing and gas detection. Compared with conventional devices, micromachined sensors are characterized by low power consumption, high sensitivity, and fast response time. Much of these gains can be attributed to the size reductions achieved by micromachining. In addition, micromachining permits easy, yet precise tailoring of the heat transfer characteristics of these devices. By simple alterations in device geometry and materials used, the relative magnitudes of radiation, convection and conduction losses and Joule heat gains can be adjusted, and in this way device response can be optimized for specific applications. The free- standing design of micromachined platforms, for example, reduces heat conduction losses to the substrate, thereby making them attractive as low-power, fast-response heaters suitable for a number of applications. However, while micromachining solves some of the heat transfer problems typical of conventionally produced devices, it introduces some of its own. These trade-offs will be discussed in the context of several micromachined thermal and gas sensors described in the literature. These include micromachined flow sensors, gas thermal conductivity sensors, pressure sensors, uncooled IR sensors, metal-oxide and catalytic/calorimetric gas sensors. Recent results obtained for a microbridge-based catalytic/calorimetric gas sensor will also be presented as a means of further illustrating the concepts of thermal design in micromachined sensors.

The MCM Designers' Access Service (MIDAS) allows designers to obtain prototype and small quantities of MCMs. To date the service has processed designs from industry, government and major universities. The service currently accesses processes at the following MCM-D foundries: nChip/Flextronics in San Jose, CA; Micromodule Systems in Cupertino, CA; and IBM Microelectronics in Hopewell Junction, NY. MIDAS provides a low cost service achieved through a multiproject environment where the customers share tooling and substrate manufacturing costs. The service offers design support, distributes foundry design kits, groups the projects onto regularly scheduled runs, places orders and supplies fully assembled modules. As well, MIDAS offers a limited selection of open tooled, second-level packages, bare tested die, and test sockets to aid with the design process. Often when investigating implementation of MCMs into a working system designers need a prototype. In many cases a foundry prefers to handle only high volume orders or imposes minimum purchase quantities. These may likely exceed the entire project budget. MIDAS functions as a technology enabler by supplying the designers with an interface `transparent' to the fabricator and common to multiple vendors. Foundries prefer to work with a single source who coordinates the details of multiple orders to spare valuable overhead. By completing front-end foundry tasks such as data preparation and mask fabrication and by grouping multiple users together on a run, MIDAS serves this purpose. Certain design conditions such as footprint size and I/O ring, layer stacking and number of layers exist to establish uniformity amongst the unrelated customers. This paper discusses the history of the service, the operating guidelines and presents an overview of how to access the service for MCM fabrication.

EMF has demonstrated the emergence of an internal structure within the power system and drive electronics for discrete and continuous piezo-coupled systems which leads to the underlying theory of quasi-active controllers (i.e. operates at high voltage, but with no net energy consumption). If the control is lossless, then it should be possible to implement control in a way which, while it requires a power source, consumes no net energy from the power source. That is a drive/control mechanism which needs a reservoir of stored energy rather than a continuous source of power. This paper is devoted to presenting a complete solution to the implementation of this new concept which is termed a synthetic lossless realization. The synthetic circuitry implements a lossless realization of quasi-active control. The synthetic concepts and circuitry are introduced and the analog and digital microcontrollers of the controlled coupled parameters are discussed.

Implementation issues represent an unfamiliar challenge to most control engineers, and many techniques for controller design ignore these issues outright. Consequently, the design of controllers for smart structural systems usually proceeds without regard for their eventual implementation, thus resulting either in serious performance degradation or in hardware requirements that squander power, complicate integration, and drive up cost. The level of integration assumed by the Smart Patch further exacerbates these difficulties, and any design inefficiency may render the realization of a single-package sensor-controller-actuator system infeasible. The goal of this research is to automate the controller implementation process and to relieve the design engineer of implementation concerns like quantization, computational efficiency, and device selection. We specifically target Field Programmable Gate Arrays (FPGAs) as our hardware platform because these devices are highly flexible, power efficient, and reprogrammable. The current study develops an automated implementation sequence that minimizes hardware requirements while maintaining controller performance. Beginning with a state space representation of the controller, the sequence automatically generates a configuration bitstream for a suitable FPGA implementation. MATLAB functions optimize and simulate the control algorithm before translating it into the VHSIC hardware description language. These functions improve power efficiency and simplify integration in the final implementation by performing a linear transformation that renders the controller computationally friendly. The transformation favors sparse matrices in order to reduce multiply operations and the hardware necessary to support them; simultaneously, the remaining matrix elements take on values that minimize limit cycles and parameter sensitivity. The proposed controller design methodology is implemented on a simple cantilever beam test structure using FPGA hardware. The experimental closed loop response is compared with that of an automated FPGA controller implementation. Finally, we explore the integration of FPGA based controllers into a multi-chip module, which we believe represents the next step towards the realization of the Smart Patch.

Piezoelectric micromotor, as one kind of the mainly actuator in Micro Electro Mechanical Systems, has been paid a great deal of attention to. This paper offers an idea of measuring the dynamic performance of a piezoelectric micromotor by means of Laser Doppler Avemometry. Based on the idea, the transient response and influence of some factors of an around travelling wave ultra motor are inspected.

This paper presents a study on the resonant frequencies of an elliptical microstrip antenna and a new simple approach to determine the resonant frequencies of any elliptical microstrip patch antenna with greater accuracy. The results obtained with this new approach are in good agreement with the available experimental results.

This work reports a direct bonding method between silicon wafers using an interlayer. Thermal oxide, sputtered silicon nitride, molybdenum film and electron-beam evaporated silicon oxide were used as an interlayer. Silicon wafers were hydrophilized by one of the host nitric acid, the sulfuric acid based solution and the ammonium hydroxide based solution, mated at class 100 hemisphere and heat treated. After hydrophilization of silicon wafers, the changes of the surface roughness' were studied by the atomic force microscopy and the voids and the non-bonded areas were inspected by the infra-red transmission microscope. The bonding interfaces of the bonded pairs were inspected by a high resolution scanning electron microscope. Surface energies and tensile strengths of the bonded pairs were also tested by the crack propagation method and the push-pull meter, respectively. Surface energy of the Si-Si wafer pair annealed at 150 degree(s)C for 48 hours was about 7200 [erg/cm²] and its tensile strength was more than 18 MPa. This tensile strength is comparable with the bulk strength of the used silicon wafer.

We performed silicon-to-In₂O₃:Sn coated glass bonding using anodic bonding process. Corning #7740 glass layer was deposited on In₂O₃:Sn coated glass by electron beam evaporation. It was confirmed that the composition of the deposited glass layer was nearly same as that of the bulk Corning #7740 glass plate using Auger electron spectroscopy. In this work, silicon and In₂O₃:Sn coated glass with the deposited glass layer can be bonded at 190 degree(s)C with an applied voltage of 60V_DC. In order to study the role of sodium ion, firstly, the bonding kinetics are modeled as resulting from the transport of sodium ions through the surface of the deposited glass layer. Secondary, the results of secondary ion mass spectroscopy analysis were used to confirm the modeled bonding kinetics of silicon-to-In₂O₃:Sn coated glass. This process can be applied for the vacuum packaging of microelectronic devices such as field emission display.

This paper presents the process and experimental results for the improved silicon-to-glass bonding using silicon direct bonding (SDB) followed by anodic bonding. The initial bonding between glass and silicon was caused by the hydrophilic surfaces of silicon-glass ensemble using SDB method. Then the initially bonded specimen had to be strongly bonded by anodic bonding process. The effects of the bonding process parameters on the interface energy were investigated as functions of the bonding temperature and voltage. We found that the specimen which was bonded using SDB process followed by anodic bonding process had higher interface energy than one using anodic bonding process only. The main factor contributing to the higher interface energy in the glass-to-silicon assemble bonded by SDB followed by anodic bonding was investigated by secondary ion mass spectroscopy analysis.

The shape memory alloy (SMA) titanium-nickel (TiNi) is used in thin film form as the basis of actuation for a reciprocating micropump. A novel configuration comprising a TiNi actuator and a polyimide diaphragm is used to perform cyclic motion while utilizing the one way shape memory effect (OWSME). The polyimide diaphragm acts as a spring to provide the bias force required for cyclic motion using the OWSME of TiNi. It also isolates the TiNi from the liquid pumped. An electrical drive signal is passed directly through the TiNi thin film. The current results in joule heating and hence a phase transformation in the SMA causing the shape memory effect. The cyclic motion of this actuator configuration cycles the volume of the pump chamber. Doubly fixed polyimide check valves ensure unidirectional flow through the pump chamber, resulting in pumping. The pump was tested with filtered DI water.

Anvik Corporation has developed a class of novel projection systems that provide both high-throughput resist patterning and dielectric photoetching for production of a variety of electronic modules including flat panel displays, multichip modules, microelectromechanical systems, and printed circuit boards. This new technology eliminates the limitations of current lithography tools, including contact and proximity tools, conventional projection systems, steppers and scanners, and direct-write machines. Further, the Anvik system is highly modular, thereby providing equipment upgradability as well as choice of user-specified system configurations. These results are achieved with a novel seamless scanning concept and stage system configurations that provide both high optical and scanning efficiencies, and enable incorporation of a high-speed automatic part loader and an automatic alignment system. We describe the new technology and present results which demonstrate 3 micron resolution in commercial photoresists.

Natural systems have evolved seamless electro-mechanical integration by exploiting intelligence and by developing multi-functional componentry. This philosophy also holds promise for creating smarter vehicles because the limitations of electronics integration and demand for new features will, sooner or later, clash with vehicle space and cost constraints. Meeting this need to maximize `functional density' and develop smarter vehicles will, however, require further improvements in several of the enabling technologies, such as digital signal processing, micro- electro-mechanical systems and smart materials.