This PDF file contains the front matter associated with SPIE Proceedings Volume 6415, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

Superlattices of silicon nanocrystals or quantum dots (QDs) are fabricated by depositing alternating layers of stoichiometric and sub-stoichiometric silicon nitride by dual-mode PECVD and subsequent high temperature annealing. NH₃, SiH₄ and Ar are used as processing gases. The formation of QDs is monitored for varying annealing temperatures using TEM and GI-XRD. Samples composed of 50 bi-layers are grown under the same conditions and annealed for two hours at temperatures ranging between 600 and 1150°C. A 50 bi-layer superlattice structure of silicon nanocrystals with an estimated average grain size of approximately 4 nm was achieved at 1000°C. The use of FTIR spectroscopy as a complementary technique for verifying the formation of silicon nanocrystals in a nitride matrix is investigated. The IR absorbance spectra for samples containing silicon nanocrystals show a distinct shoulder at 1080 cm^-1 corresponding to the Si-O-Si stretching mode possibly due to oxidation. Preliminary evidence is also presented showing the possible formation of α-Si₃N₄ nanocrystals at 1100 and 1150°C.

Several sonication procedures were performed on multi-walled carbon nanotubes (MWNTs) in water by varying the length of time, the output power and the type of sonicating horn. Depending on the sonicating conditions, the multi-walled carbon nanotubes (MWNTs) could be well or poorly exfoliated and dispersed. Poly (vinyl alcohol) (PVA) and MNWT (0.5 wt%) composites were cast from the PVA/MWNT aqueous mixture. Enhancement of the mechanical properties of the composites was related to two factors: (1) crystallinity formed at the PVA and MWNT interface and (2) the size of nanotube agglomerates. The poorly dispersed solution produced nanotube agglomerates with the size of 50-100 μm that did not induce crystallization at the polymer/nanotube interface. They became stress concentrators reducing the Young's modulus and the tensile strength. Optimized sonication procedures resulted in well-dispersed nanotube agglomerates of submicron dimensions efficiently enhancing the mechanical properties. As centrifugation facilitated the removal of large agglomerates, noticeable enhancement of mechanical properties of the composites was achieved.

In this paper a new approach for directly organizing single-walled carbon nanotubes (SWCNTs) onto a silicon (100) surface by the surface condensation reaction with hydroxyl terminated silicon is presented. X-ray photoelectron spectra, Raman spectroscopy and atomic force microscopy show that the shortened SWCNTs have been organized successfully on silicon. The optical properties of SWCNT array exhibit strong fluorescence in the visible wavelength range from 650-800 nm. The fluorescence can be attributed to the coupling effects between attached SWCNTs and silicon substrate.

This paper discusses the self-assembled growth of In(Ga)As/GaAs quantum dots by metal-organic chemical vapor deposition and their application to diode lasers and integrated opto-electronic devices. After an extensive study of the growth parameters high densities (3-4×10¹⁰cm-²) of defect free quantum dots have been achieved and ground state lasing demonstrated for diode lasers with 5 stacked layers of quantum dots in the active region. This presentation will review the important growth parameters and the lasing characteristics of quantum dot lasers. Results for selective area epitaxy of quantum dots using SiO₂ patterning will also be presented. Selective area epitaxy has been used to form quantum dots with different wavelength/bandgap in different regions of a GaAs substrate and has led to the integration of a quantum dot laser and waveguide.

Silicon nanostructures based on silicon quantum dots (SiQDs) in a silicon dielectric are being investigated for application to Si based tandem cells. The main challenge for such a structure is to obtain sufficient carrier mobility and hence a reasonable conductivity. It is believed that the conductivity of such novel SiQDs embedded in a silicon dielectric matrix is controlled by the close spacing of the SiQDs. In this study we grew a-SiO_x/a-SiO₂ ordered arrays by reactive RF magnetron co-sputtering. The composition of the SiO_x (12. The Raman scattering spectra presented in this study suggest a dot size-dependent peak below 520 cm^-1 (I_nc) and an inter-dot spacing-dependent shoulder between 495 and 500 cm^-1(I_s). The correlation between crystalline silicon density and ratio of the relative integrated intensity of SiQDs and its shoulder bands are presented. The size of the SiQDs is also confirmed by structural analysis through transmission electron microscopy (TEM) and X-ray diffraction (XRD). Initial analysis of the relationship between the relative integrated intensity (I_nc/I_s) and conductivity of SiQD superlattices with various compositions of the SiOx are presented.

GaN exhibits unique physical properties, which make this material very attractive for wide range of applications and among them ultraviolet detection. For the first time a MSM type UV photodetector structure was manufactured on a 2.2 μm. thick GaN membrane obtained using micromachining techniques. The low unintentionally doped GaN layer structure was grown by MOCVD on high resistivity (ρ<10kΩcm) <111< oriented silicon wafers, 500μm thick. The epitaxially grown layers include a thin AlN layer in order to reduce the stress in the GaN layer and avoid cracking. Conventional contact lithography, e-gun Ni/Au (10nm /200nm) evaporation and lift-off techniques were used to define the interdigitated Schottky metalization on the top of the wafer. Ten digits with a width of 1μm and a length of 100μm were defined for each electrode. The distance between the digits was also 1μm. After the backside lapping of the wafer to a thickness of approximately 150μm, a 400nm thick Al layer was patterned and deposited on the backside, to be used as mask for the selective reactive ion etching of silicon. The backside mask, for the membrane formation, was patterned using double side alignment techniques and silicon was etched down to the 2.2μm thin GaN layer using SF₆ plasma. A very low dark current (30ρA at 3V) was obtained. Optical responsivity measurements were performed at 1.5V. A maximum responsivity of 18mA/W was obtained at a wavelength of 370nm. This value is very good and can be further improved using transparent contacts for the interdigitated structure.

In this contribution we propose an iterative scheme for the solution of the coupled Poisson-Schroedinger system in a self-consistent manner. The developed methodology allows us to analyze the combined effects of piezoelectricity, spontaneous polarization, and the charge density in low-dimensional semiconductor nanostructures. These effects are analyzed here on an example of a wurtzite type semiconductor heterojunction. It is shown that such effects may influence substantially the electronic states and quasi-Fermi level energies of the nanostructures, in particular when compared to one-step calculations based on the conventional schemes. A major emphasis is given to two different types of mechanical boundary conditions.

MEMS microshutter arrays (MSAs) are being developed at NASA Goddard Space Flight Center for use as an aperture array for the Near-Infrared Spectrometer (NirSpec). The instruments will be carried on the James Webb Space Telescope (JWST), the next generation of space telescope after Hubble Space Telescope retires. The microshutter arrays are designed for the selective transmission of light with high efficiency and high contrast. Arrays are close-packed silicon nitride membranes with a pixel size of 105x204 μm. Individual shutters are patterned with a torsion flexure permitting shutters to open 90 degrees with a minimized mechanical stress concentration. Light shields are made on each shutter for light leak prevention to enhance optical contrast. Shutters are actuated magnetically, latched and addressed electrostatically. The shutter arrays are fabricated using MEMS technologies. Single-side indium flip chip bonding is performed to attach microshutter arrays to substrates.

In recent years for the fabrication of millimetre wave circuits, the removal of the substrate has been proposed as a solution for the reduction of losses, especially for silicon substrates. However, the micromachining of GaAs is an exciting less explored alternative for manufacturing high performance communication systems. GaAs micromachining is very interesting for the millimeter and submillimeter wave applications, due to the potential for easy monolithic integration of passive circuit elements with active devices manufactured on the same chip. This paper presents the monolithic integration of a two-director membrane supported Yagi-Uda antenna with a Schottky diode, both having as support a 2 μm thick GaAs membrane. The design was based on the full-wave electromagnetic simulation software Zeland-IE3D. The following Molecular Beam Epitaxy (MBE) structure was grown on a semiinsulating GaAs wafer: 0.2 μm thin AlxGa_1-x As layer with x > 0.55 (the etch-stop layer) followed by a 2 μm Low Temperature (LT) GaAs layer ("the membrane layer") and then by a 0.3 μm thin GaAs, (1x10¹⁸ cm^-3-"ohmic layer"). Finally a 0.3 μm thin GaAs (1x10¹⁷ cm^-3-"Schottky layer") was grown. An eight-mask process was developed for the receiver manufacturing. The process includes some difficult steps regarding the integration of a very small Schottky diode (with a diameter of about 3 μm) with the antenna with dimensions of a few millimeters, the polyimide-bridge manufacturing, and the membrane formation using Reactive Ion Etching (RIE). The receiver characterization, including the isotropic voltage sensitivity, was performed using "on wafer" measurements and has shown a good agreement with the simulated results. High performance receiver circuits for operating frequency of 45 GHz have been demonstrated. The technology developed can be used for applications up to THz.

This paper reports the results of theoretical and experimental investigations of reciprocating thermocapillary motion of a liquid plug in microchannels. A one-dimensional analytical model for the transport of micro plugs in a capillary was established. The model consists of a system of two transient one-dimensional equations: one for temperature spreading in the capillary wall and one for the dynamics of surface tension driven movement of the plug. Surface tension depends strongly on temperature. Thus, a transient temperature distribution leads to a gradient of surface stress across a liquid plug. This surface stress difference leads to the movement of the liquid plug. For the experimental investigation two heaters were used for the periodic temperature gradient. Each of the heaters was activated alternatively to induce the reciprocating motion of the liquid plug. For quantitative evaluation, the position of the plugs was captured and evaluated with a CCD camera. This paper focuses on analysing the results of this motion at different switching frequencies. The results show that the motion of the plug exhibits a chaotic characteristics at high switching frequencies. This actuation concept has potential applications in post-processing stages for droplet-based microfluidics. The chaotic motion can be explored for efficient mixing in microplugs.

An important technological barrier in the development of microrobotic systems is the lack of compact sensor-actuator systems. This paper presents a piston-cylinder fluidic microactuator with an integrated inductive position sensor. Such positioning systems offer great opportunities for all devices that need to control a large number of degrees of freedom in a restricted volume. The main advantage of fluidic actuators is their high force and power density at microscale. The outside diameter of the actuator developed in this research is 1.3 mm and the length is 15 mm. The stroke is 12 mm, and the actuation force is more than 0.4 N at a supply pressure of 550 kPa. The position sensor consists of two coils wound around the cylinder of the actuator. The measurement principle is based on the change in coupling factor between the coils as the piston moves in the actuator. The sensor is extremely small since one layer of 25 μm copper wire is sufficient to achieve an accuracy of 10 μm over the total stroke. Measurements showed that the actuator achieves a positioning accuracy of 20 μm in closed loop control.

This paper characterises a novel Chemical Mechanical Polishing (CMP) based process for the fabrication of nanometer wide transducer gaps for RF MEMS resonators. The process requires one photolithographic step less than previously reported fabrication methods and does not super from transducer gap widening, which otherwise strongly affects the impedance of manufactured resonators. CMP test masks were used to evaluate the ability to produce nanometer wide planarised capacitive transducer gaps and to determine the planarity of CMP based processing. As a result of this work, pattern dependent removal rates for polysilicon have been determined and design guidelines defined to optimise the yield of CMP fabricated resonators.

Poly-L-Lactides(PLLA) is a biodegradable polymer material which is sensitive to X-ray as a resist and free of stress crack formation. The fabrication technique to generate the PLLA micro structures with the very smooth sidewall is demonstrated. The function of X-ray on PLLA polymer material is breaking the PLLA polymer main chain and generating intermediates which can be degraded further and finally dissolved by the solvent interaction. In this paper, we have illustrated PLLA polymer is a new resist material for x-ray lithography and can be developed in alkaline developers after x-ray exposure. Various polymer structures are fabricated using this novel X-ray lithography technique. The PLLA structure sidewall obtained by this process is very smooth compared with that of other micromachining methods. The result after 0.02Ahour X-ray exposure dosage and developed in NaOH (1N) developer for 1 hour at room temperature shows the smooth sidewall by consuming PLLA to generate lactic acid salts. The depth of the micro PLLA structure is about 150μm and the RMS value of the sidewall roughness was within 200nm. The data of exposure doses against the processed depth on the PLLA sheet is shown.

Emerging 3D-SiP technologies and high volume MEMS applications require high productivity mass production DRIE systems. The Alcatel DRIE product range has recently been optimized to reach the highest process and hardware production performances. A study based on sub-micron high aspect ratio structures encountered in the most stringent 3D-SiP has been carried out. The optimization of the Bosch process parameters have shown ultra high silicon etch rate, with unrivaled uniformity and repeatability leading to excellent process yields. In parallel, most recent hardware and proprietary design optimization including vacuum pumping lines, process chamber, wafer chucks, pressure control system, gas delivery are discussed. A key factor for achieving the highest performances was the recognized expertise of Alcatel vacuum and plasma science technologies. These improvements have been monitored in a mass production environment for a mobile phone application. Field data analysis shows a significant reduction of cost of ownership thanks to increased throughput and much lower running costs. These benefits are now available for all 3D-SiP and high volume MEMS applications. The typical etched patterns include tapered trenches for CMOS imagers, through silicon via holes for die stacking, well controlled profile angle for 3D high precision inertial sensors, and large exposed area features for inkjet printer head and Silicon microphones.

Strontium-doped lead zirconate titanate (PSZT) is a piezoelectric ceramic with relatively high values of piezoelectric coefficients. Perovskite oriented PSZT thin films are also reported to exhibit a variety of other properties including ferroelectricity and pyroelectricity. This paper reports on a study of the surface morphology and resulting stress of PSZT thin films, deposited under a variety of RF magnetron sputtering conditions. The study compares PSZT thin films deposited on metal (gold and platinum) coated silicon wafers. The surface morphology of the deposited PSZT thin films was studied using Atomic Force Microscopy (AFM). Grain size and average surface roughness measurements were used to study the quality of the films. The thin film stress was determined using the changes in the radius of curvature of the sample due to an added layer of thin film, and by applying Stoney's equation to relate the stress to the radius of curvature. The variations in the level of stress for different thermodynamic conditions during RF magnetron sputter deposition are also reported.

The paper presents two deposition methods for generation of SiN_x layers with "zero" residual stress in PECVD reactors: mixed frequency and high power in high frequency mode (13.56 MHz). Traditionally, mix frequency mode is commonly used to produce low stress SiN_x layers, which alternatively applies the HF and LF mode. However, due to the low deposition rate of LF mode, the combined deposition rate of mix frequency is quite small in order to produce homogenous SiN_x layers. In the second method, a high power which was up to 600 W has been used, may also produce low residual stress (0-20 MPa), with higher deposition rate (250 to 350 nm/min). The higher power not only leads to higher dissociation rates of gases which results in higher deposition rates, but also brings higher N bonding in the SiN_x films and higher compressive stress from higher volume expansion of SiN_x films, which compensates the tensile stress and produces low residual stress. In addition, the paper investigates the influence of other important parameters which have great impact to the residual stress and deposition rates, such as reactant gases flow rate and pressure. By using the final optimized recipe, masking layer for anisotropic wet etching in KOH and silicon nitride cantilever have been successfully fabricated based on the low stress SiN_x layers. Moreover, nanoporous membrane with 400nm pores has also been fabricated and tested for cell culture. By cultivating the mouse D1 mesenchymal stem cells on top of the nanoporous membrane, the results showed that mouse D1 mesenchymal stem cells were able to grow well. This shows that the nanoporous membrane can be used as the platform for interfacing with living cells to become biocapsules for biomolecular separation.

We experimentally investigate the room temperature ferromagnetism (RTFM) observed in Co implanted anatase TiO₂ thin films. TiO₂ thin films were prepared by RF sputtering onto thermally grown oxide layers on Si substrates. Cobalt implantation was performed using a metal vapor vacuum arc ion source at an implant dose of 4 x10¹⁶ cm^-2. Post annealing was performed in a vacuum chamber at various temperatures up to 700°C for 2 or 4 hours. Characterization of these films as-implanted and after thermal annealing under various conditions was performed using Rutherford backscattering spectrometry, transmission electron microscopy, x-ray diffractometry and vibrating sample magnetometry. Clear RTFM properties were observed in all samples. The M_S value showed a general increase trend with increasing annealing time with higher values at higher annealing temperatures. Quite a number of samples showed Ms values exceeding the bulk Co value of 1.69_μB/Co atom after annealing. The maximum MS value observed is about 3.16_μB/Co atom for the sample annealed at 700°C for 4 hours. Such high M_S values indicate that the RTFM must not come from Co clusters alone. Possible origins of the RTFM properties are discussed in conjunction with the structural properties.

Terahertz time-domain spectroscopy (THz-TDS) is able to extract optical or dielectric properties of materials, whether in the solid, liquid, or gas phase, in the T-ray frequency region. Spectroscopy of a liquid or gas often requires a receptacle to confine the sample. In order to allow T-rays to probe the sample effectively, the receptacle must have T-ray transparent windows. However, even though windows are transparent to T-rays, attenuation exists, because of multiple reflections at air-window and window-air interfaces, which accounts for a major energy loss. Due to the recent emergence of T-ray technology, there has been very little work carried out to-date on the reduction of reflection losses. This paper analyses the reduction of T-ray reflection loss by means of an antireflection coating. Because T-ray wavelengths are much larger than visible wavelengths, the antireflection layer thickness for T-rays is much larger than the usual optical case. This creates an interesting opportunity for retrofittable antireflection layers in T-ray systems. In the experiment, a coating material made from polyethylene sheets is applied onto the surfaces of a silicon window. The coated window shows enhancement of the transmittance within a range of frequencies.

In this study, a sputtering technique for a Bio-MEMS thin film piezoelectric actuator is developed, by employing a newly designed biocompatible piezoelectric material MgSiO3 that has a tetragonal perovskite lattice crystal structure. This crystal structure was designed by using numerical analyses, such as the HSAB rule, the geometrical compatibility assessment and the first principle based DFT calculation. In general, MgSiO3 has an orthorhombic perovskite structure in the nature. Therefore, we try to generate a tetragonal structure by employing 1) the helicon wave plasma sputtering (HWPS) method, which can produce large energy atoms under a low working pressure and easy to control the lattice constant for growing the tetragonal structure of MgSiO3 and 2) a bio-compatible substrate Ir/Ti/Si, to produce a thin film of MgSiO3 tetragonal perovskite. Ir/Ti/Si substrate has better compatibility with MgSiO3 (111) plane, because of its close lattice constant. An optimal condition of HWPS to generate MgSiO3 tetragonal perovskite structure was sought by using the experimental design method and the response surface method. We found that 1) the substrate temperature and 2) the target composition ratio are significant influent factors for MgSiO3 film generation. In this searching process, we evaluated the properties of MgSiO3 films by 1) the surface roughness measured by AFM, and 2) the chemical compositions measured by XPS, and 3) the crystal structure by XRD. Finally, MgSiO3 thin film was successfully fabricated and the piezoelectric and ferroelectrics properties were measured.

Fabrication processes for MEMS are characterized by a variety of different process technologies and materials. Unlike in microelectronics the fabrication process is relevant to all design stages within the design flow. Discovering the correct combination of process steps, materials and process parameters usually requires a large number of experiments. This paper presents a new software system that supports the MEMS designers in managing their process knowledge and in performing virtual experiments using SILVACO TCAD tools.

Recent advances in UV laser machining have allowed the development of accurate and rapid prototyping of micro scale devices. Two examples are presented of how modern UV laser micro machining may be applied to novel applications in engineering research and the development of state of the art micro sensors for structural health monitoring. We also show how micro device development is now a rapid process where novel procedures allowing the manual handling of work pieces may be used to make two layer laser machined devices with alignment to tens of microns.

Photolithography is the most important process used to pattern the surface of silicon wafers in IC fabrication. It has shown high performance but its use is not cost-effective for small series or prototyping as it necessitates a costly infrastructure (mask aligner) and requires the fabrication of masks which can be expensive and timeconsuming. Recently, the high resolution achieved by ink-jet printer (> 1200 DPI) starts to make an interesting alternative to obtain a patterned protective layer instead of using photolithography. This is particularly true for MEMS which often need a resolution of only 10 to 20 μm. After studying the different architecture of inkjet printer available in the market, a commercial S$100-printer was selected and modified to allow printing on a rigid silicon wafer. We then developed three different patterning processes using the printer. In a first process the ink was directly used as a protective layer for patterning. A second process modified the photolithography by using the printed ink as a photo-mask on a spun layer of photoresist. In each case we had to modify the surface energy of the wafer by surface treatment to improve the resolution. Finally we replaced the ink with a modified photoresist solution and directly printed a protective mask onto the wafer. Design of Experiment (DOE) methods were systematically employed to study the main and interaction effects of the parameters on the lithography and on the pattern transfer. The series of experiment showed that off-the-shelf ink-jet printer could be used easily for pattern with a resolution below 50 μm, but could not yet reach the 20 μm range.

We present the design and fabrication of a micro-electromechanical system (MEMS) device for cell and particle delivery using a combination of AC electrokinetic fluidic flow and negative dielectrophoresis (DEP) force. An array of interdigitated asymmetric microelectrode pairs were used in the planar device. The electrodes produced a net charge in the surrounding fluid, generating an AC electrokinetic fluidic motion. A non-uniform electric field with low actuation frequency from the microelectrode pairs resulted in a negative DEP force, which was responsible for pushing delivery particles away from sedimentation. The experimental results showed that the flow velocity increased rapidly from 267 μm/min to 394 μm/min when the applied frequency was increased from 10 kHz to 70 kHz for a cell-suspending medium buffer solution with a conductivity of 4.7 μS/cm. A maximum delivery velocity of 801 μm/min was obtained when the buffer conductivity was increased to 47 μS/cm with an actuation frequency of 100 kHz.

The purpose of this research was to model, design and fabricate a biodynamic analysis microsystem required for the determination of various molecular transport properties of the non-Newtonian biological fluids. In order to achieve this, a lab-on-a-chip device is studied. The microsystem consists of a microchannels system and gear wheels for the rotator pump and for the detection system. The microchannel system developed satisfies the objectives for the study of microcirculation and characterization of cell rheological properties, functions and behavior. The microchannel types are: straight, bifurcated, stenosed and endothelial profiled. Some simulations were made in order to provide an idea about blood flow through blood vessels and microchannels. The gear wheel was fabricated using the silicon surface micromachining technology, combining the undercut and refill technique with pin-joint bearing permitting the fabrication of bushings. A giant magnetoresistive sensor with a non-contacting transduction mechanism, in full Wheatstone bridge configurations with four active resistors in the middle of the sensitive structure and four shielded reference resistors, very attractive for detection of low magnetic fields in lab-on-a-chip applications, is used to transform the rotor rotation rate into an electrical signal.

We present a novel technique for immobilizing nanoparticles on a substrate. This method contains two techniques, which are a preparing technique of self-assembled monomolecular layers (SAMs) terminated in an epoxy group or an amino group on surface of nanoparticles or a substrate and a reaction technique between the epoxy and amino groups. The epoxy terminated SAMs or the amino terminated SAMs were prepared on nanoparticle surfaces or a substrate surface by a chemical adsorption technique using 3-glycidoxypropyltrimethoxysilane or (3-aminopropyl) trimethoxysilane. The particles dispersed in an organic solvent were coated on the substrate, and then the epoxy and amino groups were reacted each other. Unreacted nanoparticles were removed by washing. As a result, the nanoparticles were immobilized to the substrate surface through covalent bonds of the epoxy-amine cross-linking. By using this method, a mono nanoparticle layer could be formed on the substrate.

Recent research revealed that microactuators driven by pressurized fluids are able to generate high power and force densities at microscale. Despite these promising properties, fluidic actuators are rare in microsystem technology. The main technological barrier in the development of these actuators is the fabrication of powerful seals with low leakage. This paper presents a seal technology for linear fluidic microactuators based on ferrofluids. An accurate design method for these seals has been developed and validated by measurements on miniaturized actuator prototypes. Our current actuator prototypes are able to seal pressures up to 16 bar without leakage. The actuator has an outside diameter of 2 mm, a length of 13 mm and the actuator is able to generate forces of 0.65 N and a stroke of 10 mm. Moreover, promising properties such as the restoration of the seal after a pressure overload have been observed.

We create long polymer nanotubes by directly pulling on the membrane of polymersomes using either optical tweezers or a micropipette. The polymersomes are composed of amphiphilic diblock copolymers and the nanotubes formed have an aqueous core connected to the aqueous interior of the polymersome. Stabilized membranes of nanotubes and vesicles were formed by the directed selfassembly of poly(ethylene oxide)-block-polybutadiene, followed by photopolymerization, initiated by UV light, to a maximum double bond conversion of 15%. The photopolymerized nanotubes are extremely robust. The applicability of photopolymerization for biophysics and bioanalytical science is demonstrated by electrophoresing DNA molecules through a stabilized nanotube with an integrated vesicle reservoir.

Design for manufacturability, assembly and reliability of MEMS products is being applied to a multitude of novel MEMS products to make up for the lack of "Standard Process for MEMS" concept. The latter has proved a major handicap in commercialization of MEMS devices when compared to integrated circuits products. Furthermore, an examination of recent engineering literature seems to suggest convergence towards the development of the design for manufacturability and reliability of MEMS products. This paper will highlight the advantages and disadvantages of conventional techniques that have been pursued up to this point to achieve commercialization of MEMS products, identify some of the problems slowing down development, and explore measures that could be taken to try to address those problems. Successful commercialization critically depends on packaging and assembly, manufacturability, and reliability for micro scale products. However, a methodology that appropriately shadows next generation knowledge management will undoubtedly address most of the critical problems that are hampering development of MEMS industries. Finally this paper will also identify contemporary issues that are challenging the industry in regards to product commercialization and will recommend appropriate measures based on knowledge flow to address those shortcomings and lay out plans to expedient and successful paths to market.

The procedure adopted for preparing the ferrite formation was found to be quite sensitive. The chlorine ion concentration and the pH in the solution has played a crucial role in retaining the initial stoichiometry of the solution in the nanoparticles. This work had the objective of studying the nanoparticle Mn-Zn ferrite obtained by the ferrioelate precursor method. In this process, Mn-Zn ferrite, synthesized through solutions of some specific salts led to the formation of crystalline power (10-30nm as evident from X-ray diffraction analysis) at a temperature of 2000C. The synthesis powders were characterized by X-ray diffractometer for identification of the crystalline phases present, by scanning electron microscopy for identification for their morphological structure and properties, thermogarvimetry and differential thermal analysis for identification of the oxidation/ reduction behaviour upon firing. The fourier transformation infrared spectroscopy (FT-IR) shows two main absorption bands v1 and v2 in the range of 4000-500cm-1and Differential Scanning Calorimetry (DSC) of the Mn0.4Zn0.6Fe2O4 powder at 5000C predicts the exothermic and endothermic reaction with the change in temperature with respect to heat flow. The synthesis route is simple, energy saving and cost effective. Details of the synthesis and characterizations of the resultant products were given.

The blood is one of the best indicators of health because blood circulates all body tissues and collects information. The COC(Cyclo Olefin Copolymer) has better various properties than PMMA(Polymethy Mechacrylate) and PC(Polycarbonate) that are widely used in biotechnology field. This paper presents a new method of plasma separation on the COC in terms of surface modification for the development of a disposable protein chip. The blood plasma separation device was composed of a whole blood inlet, microchannel with filtration region of micropillars, micropump with microheater, and a blood cell outlet. Micropump with microheater was designed by ANSYS and flow model in the microchannel was designed by CFD-ACE⁺ simulators. We successfully fabricated a polymer based microfluidic device for blood plasma separation by MEMS(Micro Electro Mechanical System) technology. By using this device, cell-free plasma was successfully obtained through the filtration from a drop of whole blood without external force of a syringe pump.

Tin sulphide films with thickness of 500~1000 nm were deposited on ITO glass substrates at 30~150°C by a thermal evaporation technique. The films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis. The vibrational property of the films was examined by Raman spectra. The SnS films are polycrystalline with a strong {111} preferred orientation, and they have orthorhombic crystal structure with a grain size of a few ten nanometers and exhibited near stoichiometric SnS composition. Their lattice parameters are a=0.4309~0.4313 nm, b=1.1263~1.1273 nm, c=0.3981~0.3990 nm which closely resembles those of bulk SnS at room temperature. And the substrate temperature has some influence on the composition and structure of the deposited films: when the substrate temperature increases from 30°C to 150°C, the grains in the films become smaller and the crystallinity has been improved. sulphide films with thickness of 500~1000 nm were deposited on ITO glass substrates at 30~150°C by a thermal evaporation technique. The films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis. The vibrational property of the films was examined by Raman spectra. The SnS films are polycrystalline with a strong {111} preferred orientation, and they have orthorhombic crystal structure with a grain size of a few ten nanometers and exhibited near stoichiometric SnS composition. Their lattice parameters are a=0.4309~0.4313 nm, b=1.1263~1.1273 nm, c=0.39810~.3990 nm which closely resembles those of bulk SnS at room temperature. And the substrate temperature has some influence on the composition and structure of the deposited films: when the substrate temperature increases from 30°C to 150°C, the grains in the films become smaller and the crystallinity has been improved.

A method is developed for producing nano-structured titanium oxide thin films using H₂ gas interaction with titanium thin film at a high temperature. These nano-structured thin films have been formed on a quartz crystal substrate. Titanium (Ti) thin films were deposited on the quartz crystal using a RF magnetron sputterer. The samples were placed in the oven at 500-800°C for 5 hours. The gas mixture of 1% H₂ in N₂ was introduced in the oven. The process of Ti annealing in the presence of H₂ carves Ti films into nano-structure shapes. The process is a gas-solid interaction. Thin films were characterised using Scanning Electron Microscopes (SEM) and X-Ray Diffraction (XRD) technique. The nano structures formed have dimensions in a range of 25nm - 150nm obtained after gas carving.

RF phase shifters find wide applications in telecommunications, satellite systems, personal wireless communication systems, radar systems, tracking systems, and sensors. They have been conventionally manufactured by semiconductor technologies which suffer from high insertion losses due to high RF series resistances. They are expensive due to fabrication and assembly costs. The RF MEMS phase shifters provide low insertion losses, low fabrication costs and high linearity compared with the semiconductor ones. Furthermore, polymer materials have demonstrated low material costs and low RF attenuations. In this work, we proposed to build RF MEMS phase shifters on polymer substrates. The proposed devices were successfully manufactured and tested from DC to 26 GHz. Our experimental results indicated more than 35 degrees phase shifts and low insertion losses.

This study investigates binary and multiple classes of classification via support vector machines (SVMs). A couple of groups of two dimensional features are extracted via frequency orientation components, which result in the effective classification of Terahertz (T-ray) pulses for discrimination of RNA data and various powder samples. For each classification task, a pair of extracted feature vectors from the terahertz signals corresponding to each class is viewed as two coordinates and plotted in the same coordinate system. The current classification method extracts specific features from the Fourier spectrum, without applying an extra feature extractor. This method shows that SVMs can employ conventional feature extraction methods for a T-ray classification task. Moreover, we discuss the challenges faced by this method. A pairwise classification method is applied for the multi-class classification of powder samples. Plots of learning vectors assist in understanding the classification task, which exhibit improved clustering, clear learning margins, and least support vectors. This paper highlights the ability to use a small number of features (2D features) for classification via analyzing the frequency spectrum, which greatly reduces the computation complexity in achieving the preferred classification performance.

The first continuous flow micro PCR introduced in 1998 has attracted considerable attention for the past several years because of its ability to amplify DNA at much faster rate than the conventional PCR and micro chamber PCR method. The amplification is obtained by moving the sample through 3 different fixed temperature zones. In this paper, the thermal behavior of a continuous flow PCR chip is studied using commercially available finite element software. We study the temperature uniformity and temperature gradient on the chip's top surface, the cover plate and the interface of the two layers. The material for the chip body and cover plate is glass. The duration for the PCR chip to achieve equilibrium temperature is also studied.

Iron-substituted SBA-15 materials (Fe-SBA-15) have been synthesized via a hydrothermal method with in situ incorporation of Fe(III) oxalate complex under strong acidic conditions. By employing the characterization techniques of XRD, UV-Vis, AAS and the physical adsorption of N₂ in combination with α_s-plot method, the textural properties of Fe-SBA-15 materials with different aging time spans of hydrothermal synthesis were investigated. The resulting Fe-SBA-15 samples exhibited highly ordered mesoporous materials. As the aging time extends over a certain value, the textural properties and amount of Fe incorporated to SBA-15 changed dramatically. The total surface areas increased due to the significant increase in the micropore after the 24-hour aging time, however, the wall thickness of the mesopore and the amount of iron formed in Fe-SBA-15 declined remarkably. The desired textural properties and high amount of Fe incorporated into SBA-15 could be attained by controlling the aging time of synthesized gel. The obtained Fe-SBA-15 materials demonstrated an excellent catalytic activity in the total oxidation of phenylsulfonephthalein (phenol red).

Titanium-containing SBA-15 mesoporous materials with Si/Ti molar ratios of 25, 50 and 100 (Ti-SBA-15) were successfully prepared by direct synthesized method using P123 as surfactant. The samples were characterized by XRD, BET, TEM and UV-Vis. It revealed at low Ti-loading (Si/Ti of 50-100), titanium was completely incorporated into SBA-15 framework, whereas at high Ti-loading (Si/Ti of 25) titanium was partially incorporated into SBA-15 framework, one part of Ti existed as extra-framework Ti (anatase phase). For comparison, Ti impregnated on Si-SBA-15 (Ti/SBA-15) was also prepared by postsynthesis method. In (*)this case, titanium was well dispersed onto the surface of SBA-15. The catalytic activities of Ti-SBA-15 with different Ti-content and Ti/SBA-15 samples were tested in the photocatalytic oxidation of red-phenol and in the photocatalytic reduction of Cr(VI) to Cr(III). The catalytic results showed that both the Ti-SBA-15 and Ti/SBA-15 solids are also the good catalysts for total photooxidation of red phenol. Especially, the tetrahedral coordinated titanium can oxidize red phenol much deeper than well dispersed titanium particles does. For photocatalytic reduction, the activities mainly depend on the number of Ti, not the state of Ti.

Nano-sized TiO₂ samples were successfully synthesized by both methods: sol-gel and hydrothermal treatment. The samples were characterized by XRD and FESEM, TEM. The XRD results revealed TiO₂ samples consisted of pure anatase phase and/or mixture of anatase-rutile phases depending on the synthesis condition. By SEM-TEM, the particle size of all TiO₂ samples was ca. 20-50nm. Nanosized TiO₂ samples were tested in the photocatalytic oxidation of redphenol and in the photocatalytic reduction of Cr(VI) to Cr(III). All samples were active in both reactions, however, a difference in photocatalytic activities between samples was observed. For comparison, P25 Degussa was also investigated. Photocatalytic performances of the samples were discussed.

Novel nano TS-1, Ti-MCM-41 and Ti-SBA-15 analogues were successfully synthesized by hydrothermal treatment using TS-1 nano-seeds as precursors. The samples were characterized by IR, XRD, FESEM, TEM and BET. The characterization results revealed that the synthesized TS-1 had microstructure with crystal size of 50 - 60 nm, Ti-MCM- 41 and Ti-SBA-15 analogues had mesostructure with high ordering. The samples were tested in photocatalytic oxidation of Red Phenol and in photocatalytic reduction of Cr(VI) to Cr(III). The samples exhibited high activities in both reactions. Photocatalytic performances of all samples were compared and discussed.

Organic-Inorganic hybrid pillar arrays have been controlled by cohesive force during drying in photolithography. Two-dimensional periodic pillars with micrometer repetitions were fabricated from an organic-inorganic hybrid material. The pillars were gathered at the top and gtop-gatheringh pillar patterns were obtained depending on pillar sizes such as height of the pillars and distance between neighboring pillars and types of rinse liquids. The top-gathering pillar patterns could be obtained easily in the pillar arrays with same structural parameters using 1-PrOH as a rinse liquid rather than water. From in situ observation of the drying rinse liquids, it was found that the drying of 1-PrOH differs from that of water in the pillar arrays because of the difference in the contact angles. Top-gathering pillars were partially introduced in a homogeneous periodic pillar array by the different pillar formations between two types of rinse liquids.

In this paper, we demonstrate a technique to fabricate nanostructure in an inexpensive way. A layer of polystyrene (PS) beads (650 nm diameter) was coated to get monolayer on silicon oxide substrate. The gap created between the aligned PS beads was used to deposit metals like Cr, Al, and Au using sputtering and e-beam evaporation techniques. The nano sphere acted as a mask to generate array of metallic nano structures. The thickness of deposited metal was varied to achieve varying height of the structures. Removal of the PS beads was done using di-chloromethane. Silicon oxide substrate along with the regularly aligned metallic nano structure thus formed, acted as a metallic mould for nanoimprinting. The pattern was then imprinted on a thin PMMA layer. Nano cavities created on the PMMA layer were of the order of metallic nano structure. Spot lithography was used to create rectangles to define the regions (or spots) of confinement for nanosphere. These regular nano pattern generated could be optimized to get good quality nano structures and has apparent application in photonic crystal formation and other nano application.

In micromachining, there is a growing interest in pattern transfer over extreme topographies. The ability to pattern a sputtered layer on the bottom of an etched recess, tens to hundreds of micrometers deep or to make an electrical connection from the bottom to the top of such a recess improves the manufacturing abilities of any micromachining facility significantly. The procedure developed in this work is suitable for such purposes, can be implemented with completely standard micromachining equipment and works on any surface. It relies on the ultra-thick high aspect ratio resist SU-8 to fill up deep pits completely, using a modified spin coating procedure. A process is demonstrated that allows 20 um wide metal connections from the bottom to the top of a 250 um isotropically etched pit to be made. The process is compared with existing alternatives.

In the present work, we report a new technique for preparing phospho-silicste-glass (PSG) films using RF magnetron sputtering process. For this, purpose, a 76 mm diameter target of phosphorus-doped silicon dioxide was prepared by conventional solid-state reaction route using P₂O₅ and SiO₂ powders. Since P₂O₅ is hygroscopic in nature, special care was taken to prevent lump formation due to moisture incorporation during the target making process. The PSG films were prepared in a RF (13.56 MHz) magnetron sputtering system at 200-300 watt RF power, 10-20 mTorr pressure and 45 mm target-to-substrate spacing without external substrate heating. The thickness, refractive index (n) and the absorption coefficient (k) of the films were measured using a thin-film analyzer. To confirm the presence of phosphorus in the deposited films, hot-probe test and the sheet resistance measurements were performed. As a final confirmatory test, a p-n diode was fabricated in a p-type Si wafer using the deposited film as a source of phosphorus diffusion. The phosphorus concentration in the target and the deposited film were analyzed using energy dispersive X-rays (EDAX) tool. The etch rate of the PSG film in buffered HF was measured to be about 30 times higher as compared to that of thermally grown SiO₂ films. The issues related to the use of RF sputtered PSG films as sacrificial layer in surface micromachining technology have been addressed.

The present work proposes an adhesive bonding technique, at wafer level, using SU-8 negative photoresist as intermediate layer. The adhesive was selective imprint on one of the bonding surface. The main applications are in microfluidic area where a low temperature bonding is required. The method consists of three major steps. First the adhesive layer is deposited on one of the bonding surface by contact imprinting from a dummy wafer where the SU-8 photoresist was initially spun, or from a Teflon cylinder. Second, the wafers to be bonded are placed in contact and aligned. In the last step, the bonding process is performed at temperatures between 100°C and 200°C, a pressure of 1000 N in vacuum on a classical wafer bonding system. The results indicate a low stress value induced by the bonding technique. In the same time the process presents a high yield: 95-100%. The technique was successfully tested in the fabrication process of a dielectrophoretic device.

Nanosphere lithography, which allows for the fabrication of patterned metal surfaces, is a simple, effective and unconventional technique that exploits a self-assembly process. Using this technique, polystyrene nanospheres with diameters of 500nm, and 100nm were assembled onto a 'muscovite' mica substrate in a hexagonally close packed monolayer array, to provide a physical mask for material deposition. Thermal evaporation was subsequently used to deposit gold through the nanosphere mask layer, to generate a periodic array of gold nanostructures. Upon changing the mask to a multi-layered array of nanospheres, slightly more complex nanostructures were achieved. However due to thermal evaporation being a high temperature process the nanostructures obtained deviated from their predicted quasi triangular shape due to a slight annealing of the polystyrene mask.

In this paper we report on the development of a new disposable manometric catheter for diagnosis of functional swallowing disorders. The function of this catheter is to measure the intrabolus and peak pressures occurring along the esophageal tract during the swallowing process. Traditionally, in hospitals the water perfusion technique is used to diagnose the disorder. Current manometric catheters developed elsewhere use a solid-state pressure sensor mounted directly on a thin catheter to measure the pressure changes. Both types of catheters are re-usable due to the high running cost, and this in turn increases the risk of contamination among patients, and creates hygiene problems. We have developed a new disposable manometric catheter which consists of a MEMS-based pressure sensor. Recent laboratory characterizations and hospital in-vivo tests show the new developed low cost disposable catheter prototype capable of measuring pressure ranges of 0 to 100mmHg. The in-vivo tests have also shown the new catheter prototype capable of measuring the peak pressure as well as the intrabolus pressure which is a very important parameter for doctors to carry out the required diagnosis.

For quite some time implantable electronic devices have been a topic of intense research. Such devices play a vital role in saving lives. Batteries were to the main source of power for micro implants in the body, and the quest has been to realize long life batteries. However, the battery size and limited lifetimes have fuelled the search for more practical alternatives¹. Hence the concept of Transcutaneous Energy Transmission (TET) has become a major aim of research in microtechnology for supplying power to micro implants. Among many other endeavours, research to optimize the efficient wireless power transmission to implants², thereby increasing lifetime of the implant and the comfort of the patient, has never been more intense. In this paper we propose to present research findings related to determination of parameters for optimal design of the power transmission system, including frequency spectrum, orientation, and component sizes. We have particularly focused on coil design implementation. Coil design is critical to efficient power transmission and data reception. We have looked at the two spiral geometries³ with different aspect ratios. Coupling factor, mutual inductance of the coil, quality factor Q, and optimal distance between transmitter and receiver units are to be investigated. Electromagnetic simulation is to be carried out using EM3DS simulation tool for integrated inductor design. It gives us an estimation of the coupling efficiency of the coil and power efficiency of the link at specified design geometries.

Deformable grating light modulator (GLM) also known as grating light valve (GLV) is a Micro-Opto-Electro Mechanical System (MOEMS) grating which is originally presented as a deformable grating optical modulator by Solgaard in 1992¹. Since then it has been developed for uses in various applications such as in display technology, graphic printing, lithography and optical communications^{2, 3}. We are proposing the use of deformable grating light modulators as dispersive element to de-multiplex optical input signals in a wavelength selective switching system which is originally presented by Mechels and Muller (2003) as a 1D MEMS-based wavelength switching system⁴. In this paper, we discuss the performance of the grating system in various geometries and designs supported with numerical simulations.