This PDF file contains the front matter associated with SPIE Proceedings Volume 8204, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Efficient bioluminescence resonance energy transfer (BRET) from a bioluminescent protein to a fluorescent protein with high fluorescent quantum yield has been utilized to enhance luminescence intensity, allowing single-cell imaging in near real time without external light illumination. We have applied this strategy to develop an autoluminescent Ca²⁺ indicator, BRAC, which is composed of Ca²⁺-binding protein, calmodulin, and its target peptide, M13, sandwiched between a yellow fluorescent protein variant, Venus, and an enhanced Renilla luciferase, RLuc8. With this BRAC, we succeeded visualization of Ca²⁺ dynamics at the single-cell level with temporal resolution at 1 Hz. Moreover, BRAC signals were acquired by ratiometric imaging capable of canceling out Ca²⁺-independent signal drifts due to change in cell shape, focus shift, etc. Taking advantage of the bioluminescence imaging property that does not require external excitation light, BRAC might become a powerful tool applicable in conjunction with so-called optogenetic technology by which we can control cellular and protein function by light illumination.

The excitation of plasmons in metallic nanostructures by light can give rise to pronounced local optical field enhancement with respect to the incident electromagnetic field. The details of these optical near fields depend sensitively on the properties of the nanostructures (material, size and shape), on the light wavelength and polarization, and also on the substrate. In this article we discuss several of these aspects influencing the near-field distribution for a given object and the resulting surface ablation by optical near fields. To this end we use both experimental and simulation techniques. Additionally we will present first results of experiments investigating the light emitted during nanoscale ablation. Finally, we will present an example how plasmon-mediated near-field effects act on the conductance of atomic-size contacts.

Imprint process to form fine structures onto a glass surface was studied with the aim of developing several functions such as antireflection, dispersion correction and polarization control. The fabrication of SiC molds with high thermal durability and mechanical strength enabled us to imprint an antireflection structure with reflectivity of 1/20 that of the polished surface in the visible wavelength region. Furthermore, such technology was successfully applied to the fabrication of antireflection lens.

In this work we present the latest results in the application of multi-photon polymerization for tissue engineering, by fabricating microstructured artificial 3D scaffolds for stem cell growth. Microstructuring of large scale 3D scaffolds is investigated and the direct laser writing technique is supplemented by fabrication by multi-beam interference and micromolding of large scale structures. Within the limitation of our study, we conclude that the proposed nonlinear direct laser writing technique offers rapid and flexible fabrication of biomedical components with required shape, pore size and general porosity. The applications could target biostable and biodegradable implants applied for bone or tissue replacement as well as drug delivery or release agents.

Holographic femtosecond laser processing is very useful for high-speed processing with low-loss of light. One of important subjects is to design a computer-generated hologram (CGH) with good performance in the processing system. We have proposed a CGH is optimized in the processing system. The latest method is the SH optimization method based on parallel SH generation. The SH method automatically incorporates the pulse duration and spatial beam profile into the CGH, and therefore gives high quality parallel laser processing. Because of the enhanced processing accuracy, smaller structures are processed with the smallest energy. We demonstrate the 18 parallel laser pulses performs the parallel processing on a glass surface with the average diameter of 271nm under the average fluence of 0.88 J/cm².

Solid oxide fuel cells (SOFC) are widely studied because of their potential usage in power source applications. At present huge attention is paid to micro solid oxide fuel cells (μ-SOFC) based on thin film technologies with power capacity in the range of several watts. Porous nickel is an important part in many types of solid oxide fuel cells. This work presents experimental results of laser micro-channel formation in the 200 nm thick nickel and platinum films for the fuel cell membranes. The four-beam interference ablation was applied for fast and parallel formation of microchannel over a large area in thin metal film on a silicon substrate for μ-SOFC. Using this technique, regularly arranged circular holes with a period of 4.2 μm were formed in the 200 nm thick nickel and platinum films. The diameter of the holes ranged from 1.7 to 2.7 μm. The area where holes were ablated by a single laser exposure was approximately 250x250 μm. A silicon substrate was chemically etched from backside to release the patterned nickel film.

Dielectrophoresis, the induced motion of polarisable particles in non-homogenous electric field, has been proven as a versatile mechanism to transport, immobilise, sort and characterise micro/nano scale particle in microfluidic platforms. The performance of dielectrophoretic (DEP) systems depend on two parameters: the configuration of microelectrodes designed to produce the DEP force and the operating strategies devised to employ this force in such processes. This work summarises the unique features of curved microelectrodes for the DEP manipulation of target particles in microfluidic systems. The curved microelectrodes demonstrate exceptional capabilities including (i) creating strong electric fields over a large portion of their structure, (ii) minimising electro-thermal vortices and undesired disturbances at their tips, (iii) covering the entire width of the microchannel influencing all passing particles, and (iv) providing a large trapping area at their entrance region, as evidenced by extensive numerical and experimental analyses. These microelectrodes have been successfully applied for a variety of engineering and biomedical applications including (i) sorting and trapping model polystyrene particles based on their dimensions, (ii) patterning carbon nanotubes to trap low-conductive particles, (iii) sorting live and dead cells based on their dielectric properties, (iv) real-time analysis of drug-induced cell death, and (v) interfacing tumour cells with environmental scanning electron microscopy to study their morphological properties. The DEP systems based on curved microelectrodes have a great potential to be integrated with the future lab-on-achip systems.

Droplet generation in microfluidics has attracted a great deal of attention due to the potential applications in many areas of science and technology. The understanding of the generation mechanism is still unsatisfactory and proposed models lack generality for different microchips with flow conditions and channel geometries. In this paper, we present new results of droplet generation in a PMMA microchip using flow-focusing technique. The current data are compared with existing published data obtained with similar generation microchip method. The dependence of the droplet size/slug length on the capillary number and ratio of the continuous phase and dispersed phase flow rates is investigated. A model has been proposed which explains well the data from several similar studies.

The Acoustics Driven Microfluidic Extensional Rheometer (ADMiER) utilises micro litre volumes of liquid, with viscosities as low as that of water, to create valid and observable extensional flows, liquid bridges that pinch off due to capillary forces in this case. ADMiER allows the study fluids that have been beyond conventional methods and also study more subtle fluid properties. We can observe polymeric fluids with solvent viscosities far below those previously testable, accentuating elastic effects. Also, it has enabled the testing of aqueous solutions of living motile particles, which significantly change fluid properties, opening up the potential for diagnostic applications.

Poly(dimethylsiloxane) (PDMS) is an elastomeric material used for microfluidic devices and is especially suited to medical and forensic applications. This is due to its relatively low cost, ease of fabrication, excellent optical transmission characteristics and its ability to support electroosmotic flow, required during electrophoretic separations. These aspects combined with its large range of surface modification chemistries, make PDMS an attractive substrate in microfluidic devices for, in particular, DNA separation. Here, we report the successful wet chemical surface modification of PDMS microchannels using a simple three step method to produce an isothiocyanate-terminated surface. Initially, PDMS was oxygen plasma treated to produce a silanol-terminated surface, this was then reacted with 3-aminopropyltriethoxysilane with subsequent reaction of the now amine-terminated surface with p-phenylenediisothiocyanate. Water contact angle measurements both before and after modification showed a reduction in hydrophobicity from 101^o for native PDMS to 94^o for the isothiocyante-terminated PDMS. The isothiocyanate-terminated surface was then coupled with an amineterminated single-stranded DNA (ssDNA) oligonucleotide capture probe via a thiourea linkage. Confirmation of capture probe attachment was observed using fluorescent microscopy after hybridization of the capture probes with fluorescently labeled complimentary ssDNA oligonucleotides.

Capillary flow in microchannels has received substantial attention of investigation recently due to its potential applications in microfluidics. This paper will report the new findings of capillary flow behavior in microfluidic Hele- Shaw flow cells. Flow cells with a rectangular cross section of 50×50, 50×500, 20×200, and 50×1000μm were used. It was observed that the shape of the meniscus varied with cell size and aspect ratio. The shape was also strongly affected by the contact lines on both sidewalls and the gas phase flow in front of the meniscus. For cells with same height, the meniscus was stretched more in the flow direction for wider cells. The measured averaged speed of the interface was 5.7, 8.3, 8.3 and ~8 mm/s for the flow cells with a cross section of 50×50, 50×500 and 50×1000μm, respectively. The speed of interface movement was not affected significantly by the aspect ratio for the values used in the current study. The average speed for the flow cells agree reasonably well with the value from the theoretical analysis.

Most automated industrial processes use Distributed Control Systems (DCSs) or Programmable Logic Controllers (PLCs) for automated control. PLCs tend to be more common as they have much of the functionality of DCSs, although they are generally cheaper to install and maintain. PLCs in conjunction with a human machine interface form the basis of Supervisory Control And Data Acquisition (SCADA) systems, combined with communication infrastructure and Remote Terminal Units (RTUs). RTU's basically convert different sensor measurands in to digital data that is sent back to the PLC or supervisory system. Optical fibre sensors are becoming more common in industrial processes because of their many advantageous properties. Being small, lightweight, highly sensitive, and immune to electromagnetic interference, means they are an ideal solution for a variety of diverse sensing applications. Here, we have developed a PLC Optical Fibre Sensor Interface Module (OFSIM), in which an optical fibre is connected directly to the OFSIM located next to the PLC. The embedded fibre Bragg grating sensors, are highly sensitive and can detect a number of different measurands such as temperature, pressure and strain without the need for a power supply.

There are a number of interrogation methods that can be used in optical Fibre Bragg Grating (FBG) sensing system. For very high frequency signals interrogating the sensor signal from an FBG is limited to two intensiometric methods, edge filter detection and power detection. In edge filter detection, a broadband light source illuminates an FBG, the reflected spectrum is then passed through a spectral filter. In power detection, a narrowband light source with a wavelength corresponding to the 3dB point of the FBG is filtered by the FBG itself. Both methods convert the spectral shift of the FBG into intensity signals. These two categories each have a number of variations, all with different performance characteristics. In this work we present a numerical model for all of these interrogation systems. The numerical model is based on previous analytical modelling, which could only be utilised for perfect Gaussian profiles. However, interrogation systems can make use of non Gaussian shaped filters, or sources. The numerical modelling enables the different variations to be compared using identical component performance, showing the relative strengths and weakness of the systems in terms of useful parameters, including, signal-to-noise ratio, sensitivity, and dynamic resolution. The two different detection methods can also be compared side-by-side using the same FBG. Since the model is numerical, it enables real spectral data to be used for the various components (FBG, light source, filters). This has the added advantage of increasing the accuracy and usefulness of the model, over previous analytical work.

Nanoparticle trapping is considered to be more challenging than trapping micron-sized objects because of the diffraction limit of light and the severe Brownian motion of the nanoparticles. We introduce a nanoparticle trapping approach based on plasmonic nanostructures, which consist of nanopillars with high aspect ratio. The plasmonic nanopillars behave as plasmonic resonators that rely on paired nano-pillars supporting gap plasmon modes. The localized surface plasmon resonance effect provides strong electromagnetic field enhancement and enables confinement of nanoparticles in three dimensional space. Numerical simulations indicate that the plasmonic structure provides stronger optical forces for trapping nanoparticles. The study of thermal effect of the plasmonic structure shows that the impact of the thermal force is significant, which may determine the outcome of the nanoparticle trapping.

Terrace-microspheres of high-index multi-component glasses (BaO-SiO₂-TiO₂, nD=1.93; BaO-ZnO-TiO₂, nD=2.2) containing various Nd³⁺ contents were used for pumping experiments to investigate the influence of Nd³⁺ content and matrix of glasses on the SRS enhancement effect. Pumping the terrace-microspheres containing low content of Nd³⁺(0.3ppm and 0.9 ppm) at 800-830nm wavelengths, Raman scattering due to glass matrix and Nd3+ fluorescence were overlapped spectrally in the wavelength region of 860~940nm. Under such conditions, Nd³⁺ works as a seeding and an amplifier of SRS, resulting in SRS enhancement at 840~940nm wavelengths. The terrace-microspheres of both highindex glasses showed SRS gain enhancement of 4 times (Normalized SRS gain = [SRS peak intensities at various pumping wavelength] / [SRS peak intensity at 790nm pumping wavelength]) and decrease in SRS thresholds from 2.5mW (λ_pump≈790nm) to 0.3mW (λ_pump≈810~830nm). On the other hand at high-content Nd³⁺ (15, 120 and 16000ppm), Nd³⁺ fluorescence intensity was far stronger than that of Raman scattering and SRS was not observed clearly. The reason why SRS decreased in the high-Nd3+-content glass spheres was discussed: Nd³⁺ absorption in the region of 890~900nm wavelengths is one of the plausible explanations. Terrace-microsphere of Nd³⁺ (0.9ppm) BaO-ZnO-TiO2 glass was also used for pumping experiment, which glass shows 30 times stronger spontaneous Raman scattering than that of silica glass, and result in strongest SRS emission was performed. The high-index multi-component terrace-microspheres containing Nd³⁺ of relatively low content have a potential application to a low-threshold spherical Raman laser for multiwavelength emission in the near-infrared region (λ=840~940nm).

Despite the fact that the performance of organic solar cells is generally susceptible to degradation by moisture exposure, there has been suggestion that the photoactive layer (P3HT) is surprisingly resilient. This work attempts to confirm the stability of P3HT as an organic solar cell material by deliberately introducing water into the photoactive layer. A dramatic step drop in device performance during cell characterization is observed approximately one day after the device has been fabricated. The time-delayed step drop in output efficiency strongly suggests that moisture has little effect on the P3HT conducting polymer.

In this study, we compare the practical implementation of both silicon and germanium Photovoltaic Power Converters (PPCs). Simulations have previously shown that silicon PPCs can produce up to 43% optical to electrical power conversion and germanium PPCs can produce conversion efficiencies as high as 22% when illuminated by 980nm light. Moreover, germanium can produce conversion efficiencies of up to 36% when illuminated by 1550nm light. Here, we compare these results to real power conversion efficiencies of off-the-shelf silicon and germanium photodiodes, producing 9.9% and 8.0% conversion efficiencies, respectively for 980nm. Furthermore, we show germanium produces conversion efficiencies up to 14.6% under illumination of 1550nm light. A discussion of the limitations is made. The results show there is a peak efficiency point corresponding to a specific input optical power. We also show that the power over fibre signal can be successfully combined with communications signals, using wavelength division multiplexing, and that the multiplexed signals can be separated without significant loss of signal, or power conversion efficiency. In addition, we investigate the affects of free space problems, such as divergence and misalignment, in both the lateral and longitudinal directions. As expected, optical alignment plays a significant role in producing maximum power conversion.

A comparison between Silicon (Si) which is an indirect band-gap semiconductor and Gallium Arsenide (GaAs) as a direct band-gap semiconductor for vertical-aligned nanowire radial pn junction-based photovoltaic (PV) devices is presented. The study takes place through determining the fill factor, the power conversion efficiency, the optimum device length and the spectrum of the quantum efficiency. The sensitivity of both Si and GaAs nanowire to temperature variations is also investigated. Finally, the array effect for nanowires of each material alone then of arrays of mixed elements' types is simulated. The results are found to be in accordance with the available experimental measurements.

The fabrication of highly ordered anodic porous alumina and its application to the fabrication of several types of functional optical devices are described. Highly ordered hole array structures of anodic porous alumina, which were formed under appropriate anodizing conditions, were applied as a starting structure in several processes for the fabrication of ordered structures used for the functional optical devices. On the basis of these processes, twodimensional photonic crystals and localized surface plasmonic devices were prepared.

In this paper we overview recent progress in ultrafast laser nanostructuring of transparent materials. A remarkable effect has also been discovered, referred to as quill or calligraphic laser writing, which reveals strong dependence of the material modification, in particular the self-assembled sub-wavelength structures in glass, on orientation of the writing direction relative to direction of the pulse front tilt. Moreover, evidence of the first order phase transition associated with self-assembled nanostructures formation was revealed and supercooled state of laser damage was observed using pulses with tilted intensity front. More recently it has been demonstrated that the tip of an ultrafast laser quill has a property that is very different from an ordinary quill. Specifically, the modification of glass can be controlled even in stationary conditions by the mutual orientation of light polarization azimuth and the pulse front tilt. More recently, the selfassembled sub-wavelength nanostructuring have been proposed for fabrication of vortex polarization converters and rewritable polarization multiplexed optical memory, where the information encoding is realized by means of two birefringence parameters, i.e. the slow axis orientation (4th dimension) and retardance (5th dimension), in addition to three spatial coordinates.

Here we report on the use of liquid crystal topological defects for photonic applications that involve optical singularities. The well-dened molecular organization around a liquid crystal defect enables the coupling between the spin and the orbital angular momentum of light. Such an optical spin-orbit coupling is a general feature of light propagation through inhomogeneous or anisotropic media, which makes liquid crystal topological defects attractive micro-structures when orbital angular momentum of light is the key ingredient of an application.

Micro and nano structuring of materials using femtosecond lasers has attracted considerable interest as a tool for fabrication of various photonic devices, such as diffractive elements, photonic crystals (PhC), optical waveguides, etc. Direct Laser Write (DLW) technique based on 3D high-resolution drawing of refractive index modulation structures is especially attractive, since it allows fabrication of 3D photonic micro- and nano-structures without the tediousness of planar microfabrication techniques borrowed from semiconductor industry (e.g., electronbeam lithography, thin film deposition, dry-etching, etc.). Here, we describe application of femtosecond DLW lithography for the fabrication of 3D PhC structures in photoresists and describe application of these structures for collimation of optical beams. Using theoretical analysis and numerical simulations we show that 3D woodpile architecture PhC enables collimation of divergent optical beams via negative diffraction in a 3D periodic structure. Using parameters of 3D woodpile structure obtained from the theoretical analysis, woodpile structures were fabricated by DLW technique and beam collimation in these structures was demonstrated experimentally.

We developed a local force measurement system of a femtosecond laser-induced impulsive force, which is due to shock and stress waves generated by focusing an intense femtosecond laser into water with a highly numerical aperture objective lens. In this system, the force localized in micron-sized region was detected by bending movement of a cantilever of atomic force microscope (AFM). Here we calculated the bending movement of the AFM cantilever when the femtosecond laser is focused in water at the vicinity of the cantilever and the impulsive force is loaded on the cantilever. From the result, a method to estimate the total of the impulsive force at the laser focal point was suggested and applied to estimate intercellular adhesion strength.

Electro cell fusion has significant potential as a biotechnology tool with applications ranging from antibody production to cellular reprogramming. However due to low fusion efficiency of the conventional electro fusion methodology the true potential of the technique has not been reached. In this paper, we report a new method which takes cell fusion efficiency two orders magnitude higher than the conventional electro fusion method. The new method, based on one-toone pairing, fusion and selection of fused cells was developed using a microfabricated device. The device was composed of two microfluidic channels, a micro slit array and a petri dish integrated with electrodes. The electrodes positioned in each channel were used to generate electric field lines concentrating in the micro slits. Cells were introduced into channels and brought in to contact through the micro slit array using dielectrophoresis. The cells in contact were fused by applying a DC pulse to electrodes. As the electric field lines were concentrated at the micro slits the membrane potential was induced only at the vicinity of the micro slits, namely only at the cell-cell contact point. This mechanism assured the minimum damage to cells in the fusion as well as the ability to control the strength and location of induced membrane potential. We introduced mouse embryonic stem cells and mouse embryonic fibroblasts to the microfluidic channels and demonstrated high-yield fusion (> 80%). Post-fusion study showed the method can generate viable hybrids of stem cells and embryonic fibroblasts. Multinucleated hybrid cells adhering on the chip surface were routinely obtained by using this method and on-chip culturing.

We have developed a new porous gradient microfluidic device based on in situ Gtn-HPA/CMC-Tyr hydrogel that comprises gelatin hydroxyphenylpropionic acid (Gtn-HPA) conjugate and carboxymethyl cellulose tyramine (CMC-Tyr) conjugate. The device is fabricated using a soft lithographic technique, in which microstructures were patterned on a thin layer of polydimethylsiloxane (PDMS) using a polymeric mold. Human fibrosarcoma cells (HT1080) were employed as invasive cancer cell model. Porosity gradients were generated by flowing pore etching fluid in the gradient generator network. Results suggested that spatial control of the porosity can be obtained, which mimics the 3-dimensional microenvironment in vivo for cell-based screening applications including real time chemotaxis, cytotoxicity, and continuous drug-response monitoring. A chemoattractant gradient is then generated and cell migration is monitored in real time using fluorescence microscopy. The viability of cells was evaluated using calcien AM stain. Herein, we successfully monitored the chemotactic responses of cancer cells, confirmed the validity of using in situ porous hydrogels as a construction material for a microchemotaxis device, and demonstrated the potential of the hydrogel with tunable porosity based microfluidic device in biological experiments. This device will also be practical in controlling the chemical and mechanical properties of the surroundings during the formation of tissue engineered constructs.

We report on the design of two different surface acoustic wave (SAW) driven rotary motors. Both designs use 20-30 MHz transducers patterned onto Lithium Niobate (LN), geometrically tailored to generate Rayleigh waves that are incident on opposing sides of each rotor. The first design exploits the efficient coupling between SAWs and fluids by use of a fluid coupling layer between the rotor and substrate, leading to rotations of a 5 mm disc shaped rotor over 2,500 rpm with a start-up torque of 60 nN m. The second design exploits a dry friction contact between the surface and rotors for further miniaturisation. In the latter design 1 mm steel rotors are driven up to 6,000 rpm with no external preload required.

Analysis of chemical warfare agents (CWAs) and their degradation products is an important verification component in support of the Chemical Weapons Convention and urgently demanding rapid and reliable analytical methods. A portable microchip electrophoresis (ME) device with contactless conductivity (CCD) detection was developed for the in situ identification of CWA and their degradation products. A 10mM MES/His, 0.4mM CTAB - based separation electrolyte accomplished the analysis of Sarin (GB), Tabun( GA) and Soman (GD) in less than 1 min, which is the fastest screening of nerve agents achieved with portable ME and CCD based detection methods to date. Reproducibility of detection was successfully demonstrated on simultaneous detection of GB (200ppm) and GA (278ppm). Reasonable agreement for the four consecutive runs was achieved with the mean peak time for Sarin of 29.15s, and the standard error of 0.58s or 2%. GD and GA were simultaneously detected with their degradation products methylphosphonic acid (MPA), pinacolyl methylphosphonic acid (PMPA) and O-Ethyl Phosphorocyanidate (GAHP and GAHP1) respectively. The detection limit for Sarin was around 35ppb. To the best of our knowledge this is the best result achieved in microchip electrophoresis and contactless conductivity based detection to date.

We studied new three-dimensional tailoring of nano-particles by ion-beam and electron-beam lithographies, aiming for features and nano-gaps down to 10 nm size. Electron-beam patterning is demonstrated for 2D fabrication in combination with plasmonic metal deposition and lift-off, with full control of spectral features of plasmonic nano-particles and patterns on dielectric substrates. We present wide-angle bow-tie rounded nano-antennas whose plasmonic resonances achieve strong field enhancement at engineered wavelength range, and show how the addition of fractal patterns defined by standard electron beam lithography achieve light field enhancement from visible to far-IR spectral range and scalable up towards THz band. Field enhancement is evaluated by FDTD modeling on full-3D simulation domains using complex material models, showing the modeling method capabilities and the effect of staircase approximations on field enhancement and resonance conditions, especially at metal corners, where a minimum rounding radius of 2 nm is resolved and a five-fold reduction of spurious ringing at sharp corners is obtained by the use of conformal meshing.

Gold-coated array patterned with tightly-packed nanospheres was developed as a substrate base for constructing SERSenriched nanogaps with Au-nanoparticles (GNPs). Using 1,2-ethanedithiol as a linker, Au-NPs (=17-40nm) were anchored covalently on the sphere-array. Thin Au layer was sputtered on the substrate to mask the citrate coating of GNPs that could demote the sensing mechanism. The negatively-charged GNP surface warrants the colloidal stability, but the resulting repulsive force keeps the immobilized NPs apart by about 40nm. The attained gap size is inadequately narrow to sustain any intense enhancement owing to the near-field nature of SERS. Minimal amount of NaCl was then added to slightly perturb the colloidal stability by reducing their surface charge. Notably, the interparticle-gap reduces at increasing amount of salt, giving rise to increased packing density of GNPs. The SERS enhancement is also found to exponentially increase at decreasing gap size. Nevertheless, the minimum gap achieved is limited to merely 7nm. Excessive addition of salt would eventually induce complete aggregation of particles, forming clustered NPs on the array. A simple sputtering-growth approach is therefore proposed to further minimize the interparticle gap by enlarging the seeded NPs based on mild sputtering. The SEM images confirm that the gap below 7nm is achievable. With advent of the colloidal chemistry, the combined salt-induced aggregation and sputtering-growth techniques can be applied to engineer interparticle gap that is crucial to realize an ultrasensitive SERS biosensor. The proposed two-step preparation can be potentially adopted to fabricate the SERS-enriched nanogaps on the microfluidics platform.

We designed and proposed a focusing device for the localization of photons in nanometric region by surface plasmon excitation. The focusing device is a metal-coated axicon prism. The cone angle of the prism and the metallic film thickness are designed to match the excitation conditions for Kretschmann configuration. A collimated Gaussian beam is irradiated to the prism and the excited surface plasmons propagate along the sides of the prism and converge at its apex. The resulting nanofocusing was investigated by the simulations and experiments of the intensity distributions around the apex of the prism. For incident radial polarization, a localized and field enhanced spot is generated by the constructive interference of surface plasmons. We observed the light scattered at the apex and the light reflected by the prism. Each polarized light of the radial, azimuthal, and linear provided field distributions of bright and dark intensities according to the surface plasmon excitation. We have demonstrated that surface plasmon waves are excited at the sides of the prism in the Kretschmann configuration and that they converge to its apex.

We investigate the synthesis of two-dimensional surface plasmon vortex power flows by a plasmonic vortex lens excited by oblique incident beams. It is shown that the plasmonic vortex lens can generate the off-centered vortex flows, the centers of which are determined by the incidence angle of the excitation beam. The theoretical analysis of the relationship between the off-center shift and the incidence angle is described. Furthermore it is shown that the illumination of two unparallel coherent incidence beams produces dual-vortex flows by the coherent superposition.

The fabrication of a three-dimensional (3D) ordered array of metal and/or metal oxide nanoparticles in an anodic porous alumina matrix and the application of a 3D array of Au nanoparticles as a substrate for the measurement of surfaceenhanced Raman scattering (SERS) are discussed. The 3D structure is prepared by a repeated process composed of the formation of nanoholes by the anodization of Al and the subsequent electrochemical deposition of a metal into the holes. The dependence of the SERS intensity on the number of layers of the Au nanoparticle array was examined. In addition, the effect of the gap size between Au nanoparticles was also investigated. The present process allows the fabrication of 3D functional optical devices based on the enhancement of the electric field of incident light.

Advanced porous materials open up new frontiers for sensing, drug delivery and host matrices for biomedical applications because selective/active release/sequestration of precise molecules is expected. Different types of materials are currently being investigated and paths which move between material optimization and patterning processes are clearly observed for mesoporous materials. Here we present our recent progress on lithographic methodologies to achieve such spatial control for ceramic mesoporous coatings with a particular focus on metal organic frameworks for emerging sensing technology.

ZnO nanostructures were grown using a simple and environmentally friendly chemical bath deposition technique on pre-treated p-type silicon substrate at temperatures below 100°C. The effects of growth parameters like seed layer density, growth time, growth temperature, precursor concentration and annealing temperature on the structural, morphological, electrical and optical properties of ZnO nanorods were systematically studied using field emission scanning electron microscopy, X-ray diffraction, photoluminescence spectroscopy and current-voltage measurements. A variety of architectures is demonstrated, ranging from single crystalline nanoparticles and c-axis orientated nanorods to highly compact crystalline thin films. Post-growth annealing at different temperatures profoundly affects the optical properties of the nanorods by, for example, reducing hydrogen- and intrinsic defect-related emission. The rectifying properties of the ZnO/Si heterojunction are discussed.

In this paper four different photopolymers are compared on the basis of their suitability for holographic data storage. The optical recording parameters of these photopolymers were directly determined using the zero spatial frequency limit. The behavior of cover plated and uncover plated material layers was analyzed. Once the main parameters were determined, we proposed a novel model to simulate the recording of relief diffractive elements onto the photopolymers without cover plating. Relief surface changes provide interesting possibilities for storing diffractive optical elements on photopolymers and are an important source of information for characterizing and understanding the material behaviour. In this paper we also present a 3-dimensional model, based on direct parameter measurements, for predicting the relief structures generated on the material. This model was successfully applied to different photopolymers with different values of monomer diffusion.

In this paper, we focus on three issues: 1) proposing a novel photonic crystal waveguide based Symmetric-Mach- Zehnder-type ultrafast all-optical switch using Quantum Dot Semiconductor Optical Amplifier (QD-SOA) and the basic parameters of the photonic crystal waveguide, 2) simulating the general features of the QD-SOA, 3)performance analysis of the all-optical switch. We find that the switching contrast ratio of this kind of all-optical switch has been enhanced due to the superior optical confinement of the photonic crystal waveguide.

Using ultrashort pulsed optical excitation and interferometric detection, we image ultrahigh- frequency surface acoustic waves on two-dimensional (2D) phononic crystals in the time domain. The samples consist of a square lattice of airfilled holes etched in a silicon substrate. Good agreement with time-domain finite element numerical simulations is obtained. The dispersion relation is derived and stop bands are revealed by means of Fourier transforms. The wave fields corresponding to acoustic eigenmodes at specific frequencies are also presented.

We demonstrate to fabricate microfluidic chips integrated with some functional microcomponents such as optical attenuators and optical waveguides by femtosecond laser direct writing for understanding phenomena and functions of microorganisms. Femtosecond laser irradiation followed by annealing and wet etching in dilute hydrofluoric acid solution resulted in fabrication of three-dimensional microfludic structures embedded in a photosensitive glass. The embedded microfludic structures enabled us to easily and efficiently observe Phormidium gliding to the seedling root, which accelerates growth of the vegetable. In addition, integration of optical attenuators and optical waveguides into the microfluidic structures clarified the mechanism of the gliding movement of Phormidium. We termed such integrated microchips nanoaquariums, realizing the highly efficient and functional observation and analysis of various microorganisms.

Laser microprocessing and nanoengineering are of great interest to both scientists and engineers, since the inspired properties of functional micro/nanostructures over large areas can lead to numerous unique applications. Currently laser processing systems combined with high speed automation ensure the focused laser beam to process various materials at a high throughput and a high accuracy over large working areas. UV lasers are widely used in both laser microprocessing and nanoengineering. However by improving the processing methods, green pulsed laser is capable of replacing UV lasers to make high aspect ratio micro-grooves on fragile and transparent sapphire substrates. Laser micro-texturing can also tune the wetting property of metal surfaces from hydrophilic to super-hydrophobic at a contact angle of 161° without chemical coating. Laser microlens array (MLA) can split a laser beam into multiple laser beams and reduce the laser spot size down to sub-microns. It can be applied to fabricate split ring resonator (SRR) meta-materials for THz sensing, surface plasmonic resonance (SPR) structures for NIR and molding tools for soft lithography. Furthermore, laser interference lithography combined with thermal annealing can obtain a large area of sub-50nm nano-dot clusters used for SPR applications.

In this study, we investigated systematically on perovskite oxides ABO₃ through first-principles calculations based on density functional theory to find novel biocompatible lead-free piezoelectric materials. Biocompatible elements were picked out with HSAB ( Hard Soft Acids and Bases ) principle at the viewpoint of interaction energy with in-vivo molecules and they were applied to A and B of perovskite oxides ABO₃. The stable combinations of constituent elements were specified with consideration for geometric and electric equilibrium condition. Then the stable cubic structure and the phonon properties were analyzed for the paraelectric non-polar phase. The soft modes, which induce a structural phase transition to non-centrosymmetric crystal structures, were distinguished with the phonon eigenfrequency and eigenvector. Additionally, insulation properties were estimated from band structure. As a result, five perovskite oxides, MgSiO₃, MnSiO₃, FeSiO₃, ZnSiO₃ and CaSiO₃, were discovered as probable materials, which have band gap and soft modes progressing into tetragonal structure of ferroelectric phases. After the stable tetragonal structures were evaluated through initial setting of atomic positions based on soft modes, their material properties such as spontaneous polarization and piezoelectric stress constant were analyzed. Computations indicated tetragonal MgSiO₃ exhibits relatively-large piezoelectricity.

Recently, the developments of lead-free materials such as BaTiO₃ have been widely investigated. However, the piezoelectricities for those materials are not superior to existing lead-included materials such as PZT. In order to design high piezoelectric materials, we propose the analytical technique, which is able to consider the influence of additives added into biocompatible lead-free piezoelectric materials BaTiO₃. Because, the additives are effective technique to improve the piezoelectricities of piezoelectric materials in general. In this research, we proposed the analytical method by using the Rietveld method to quantitatively confirm the changing of diffraction intensities for BaTiO₃ (which shows relative relationship with piezoelectricity experimentally) with changing the additive atoms at the appropriate chemical composition. Especially, the factors in the equation in regard to XRD (X-ray diffraction) diffraction intensities in the Rietveld method in order to change and improve piezoelectricities by various additives were investigated by comparing to the XRD intensity for non-added BaTiO₃. Firstly, the theoretical diffraction pattern in regard to BaTiO₃ Perovskite crystal structure were characterized by using the non-linear least square method. Secondly, the diffraction intensities for BaTiO₃ material added various additives to displace B-site of Perovskite structure for BaTiO₃ at the rate of 10% were calculated. Finally, the difference diffraction intensities between BaTiO₃(111) and BaTiO₃(111) added additives such as a periodic atoms were also calculated. As a result, the correlation factor between the atomic scattering factor and the changing amount of the diffraction intensity of BaTiO₃(111) shows strong negative correlation of -0.997 to improve piezoelectricity. And also it is confirm that the X-ray absorption rate contributes to the change in the diffraction intensity periodically in local region.

We demonstrate an electrochemical switching of conformation of surface-bound polymer brushes, by grafting environmentally sensitive polymer brushes from an electrochemically-active conducting polymer (ECP). Using atom transfer radical polymerization (ATRP), we grafted zwitterionic polymer brushes, poly(3-(methacryloylamino)propyl)- dimethyl(3-sulfopropyl)ammonium hydroxide) (MPDSAH), from a surface initiated poly(pyrrole-co-pyrrolyl butyric acid) film. The changes in ionic solution composition in electrical double layer at the surface resulting from oxidation and reduction of the ECP trigger a switch in conformation of surface-bound poly(MPDSAH), demonstrated here by electrochemical impedance spectroscopy (EIS). The switch is also dependent upon temperature. We speculate that the synergistic combination of properties embodied in these "smart" materials may find application in electrochemical control of surface wetting and of interaction with biomolecules and living cells.

We report on the design and simulation of a novel Silicon-On-Insulator waveguide structures which when excited with TM guided light, emit TE polarized radiation with controlled radiation characteristics[1]. The structures utilize parallel leaky waveguides of specific separations. The structures are simulated using a full-vector mode-matching approach which allows visualisation of the evolution of the propagating and radiating fields over the length of the waveguide structure. It is shown that radiation can be resonantly enhanced or suppressed in different directions depending on the choice of the phase of the excitation of the waveguide components. Steps toward practical demonstration are identified.

Prototyping a Micro Electro Mechanical System (MEMS) device is a very different process to that employed for a standard Integrated Circuit (IC) or Printed Circuit Board (PCB). While the manufacturing methods for MEMS devices largely derive from the IC industry MEMS present many unique manufacturability challenges. These challenges typically relate to two distinct features, specifically; mechanics of the device and the packaging of the device. This paper discusses some of the potential pitfalls in the manufacture of a MEMS prototype; more specifically the paper considers issues leading to low yield rates in a MEMS prototype developed by the authors and then discusses possible improvements to enable a better chance of success. This discussion first identifies some of the more significant MEMS sensor design features that contributed to a low yield and then presents design improvements that could significantly increase the yield. Following this is the identification of several issues involved in packaging the sensor, which had the effect of reducing the yield further; in this case improvements in the packaging are suggested. Also discussed are some general prototyping problems researchers may face that with careful planning may be avoided.

In this study a 3-D finite element analysis for cantilever plate structure excited by giving unit deflection at free end is presented. Finite Element Modeling based on ANSYS12.0 package using modal analysis and harmonic analysis is used in this study for cantilever plate structure by patch type of piezoelectric plates of PZT-5H4E as a piezo material and steel as a substrate material for Cantilever Beam. This study aims to investigate the influence of different geometry parameters like, length and width & position of piezo patches on voltage generation & try to find out optimal geometrical dimensions of piezoelectric beam for maximum energy harvesting. ANSYS-12.0 is used as optimization tool. Here the basic modeling with an equivalent circuit is done initially by considering some specific dimensions of beam. Then simulation of the same is done by varying different geometrical parameters where effect of change in length of piezo patch is analyzed first .The second affecting parameter considered is change in Width of piezo patch and last one is the position of piezo patch along the length of beam is analyzed, where output is measured in turn of voltage generated. This study aims to investigate the Optimum placement of piezoelectric actuators in a cantilever beam for maximum energy harvesting.

In this paper we describe the spatial surface chemical modification of bonded microchannels through the integration of microplasmas into a microfluidic chip (MMC). The composite MMC comprises an array of precisely aligned electrodes surrounding the gas/fluid microchannel. Pairs of electrodes are used to locally ignite microplasmas inside the microchannel. Microplasmas, comprising geometrically confined microscopic electrically-driven gas discharges, are used to spatially functionalise the walls of the microchannels with proteins and enzymes down to scale lengths of 300 μm inside 50 μm-wide microchannels. Microchannels in poly(dimethylsiloxane) (PDMS) or glass were used in this study. Protein specifically adsorbed on to the regions inside the PDMS microchannel that were directly exposed to the microplasma. Glass microchannels required pre-functionalisation to enable the spatial patterning of protein. Firstly, the microchannel wall was functionalised with a protein adhesion layer, 3-aminopropyl-triethoxysilane (APTES), and secondly, a protein blocking agent (bovine serum albumin, BSA) was adsorbed onto APTES. The functionalised microchannel wall was then treated with an array of spatially localised microplasmas that reduced the blocking capability of the BSA in the region that had been exposed to the plasma. This enabled the functionalisation of the microchannel with an array of spatially separated protein. As an alternative we demonstrated the feasibility of depositing functional thin films inside the MMC by spatially plasma depositing acrylic acid and 1,7-octadiene within the microchannel. This new MMC technology enables the surface chemistry of microchannels to be engineered with precision, which is expected to broaden the scope of lab-on-a-chip type applications.

The transmission and localized electric field distribution of nanostructures are the most important parameters in the plasmonic field for nano-optics and nanobiosensors. In this paper, we propose a novel nanostructure which may be used for nanobiosensor applications. The effect of nanoholes on the plasmonic properties of star nanostructure was studied via numerical simulation, using the finite-difference time-domain (FDTD) method. In the model, the material type and size of the nanostructures was fixed, but the distance between the monotor and the surface of the nanoholes was varied. For example, nanoholes were located in the center of the nanostructures. The simulation method was as follows. Initially, the wavelength of incident light was varied from 400 to 1200 nm and the transmission spectrum and the electric field distribution were simulated. Then at the resonance wavelength (wavelength where the transmission spectrum has a minimum), the localized electric field distribution was calculated at different distances from the surface of the nanostructures. This study shows that the position of nanoholes has a significant effect on the transmission and localized electric field distribution of star nanostructures. The condition for achieving the maximum localized electric field distribution can be used in nano-optics and nanobiosensors in the future.

Interconnect wires are major technology components of modern high-speed integrated circuits. To overcome the latter's degradation caused by increasing miniaturization, there is an urgent need to look for alternative technologies. Since carbon based materials generate promising results, this paper focuses on describing the electrical properties of carbon based materials, in particular the use of graphene nanoribbon (GNR) as well as trilayer graphene nanoribbon (TGN) as next generation interconnects: since the conductance of TGN is less affected by external fields compared to GNR, it forms an improved choice for on-chip interconnects. The conductance model of TGN is derived and discussed in detail.

Experiments in photonics tend to be reserved for postgraduate laboratories, where suitable equipment and resources are available. Simple optical fibre experiments may be included in some undergraduate programs, possibly utilising polymer optical fibres with LEDs and phototransistors, or with the use of bulk optical components and glass optical fibre elements. However, real optical fibre communication systems and optical fibre sensing systems utilise more complex devices, such as optical fibre Bragg gratings. With the availability of optical components in the 850nm wavelength range, a variety of practical systems can be realised using industry standard components. We show how to mitigate a large portion of the cost associated with the implementation of experiments utilising these 850nm components. The limiting factor associated with the implementation of 1550nm based systems is the cost associated with spectral measurements in this wavelength range. Given a bench top optical spectrum analyser costs $10,000s; this is not something that can be made available to students in undergraduate laboratories in bulk. The solution was to make use of the new low cost USB based spectrometers, available from a number of manufacturers. In combination with devices such as couplers, circulators, isolators, wavelength division multiplexing filters, and Bragg gratings, all operating in the 850nm, a number of different sensing and communications systems can be realised.

Creating and monitoring micro-scale thermal transfer in micro-structured thin polymer films is presented in this study. Thermal imaging is captured using IR camera equipped with optics designed for the mid- and long- IR wavelengths. The non-contact thermal imaging method is preferred to visualize the distribution of temperature and characterizes the thermal properties of complex multi-component/layered structures of thermal functioning materials. The work is to present a method for thermal wave imaging that is applied to measure the thermal diffusivity of the micro-structured polymer thin films using a modulated laser-diode spot heating irradiated to the rear surface of the film, observed at different modulation frequencies. The procedure is based on the micro-scale thermography and the analysis is based on the computational phase lock-in system for the temporal evolution extracted from the sequence of infrared image. The in-plane surface profiles of the amplitude and phase are precisely calculated and the principle for eliminating the effects of heat loss is examined.

Digital holography is widely used as a high resolution metrological technique in many domains. As a coherent imaging method, the speckle noise is inherent in the system and degrades image quality and optical resolution. An improved fiber-space-hybrid lensless Fourier-transform digital holography system is proposed. Multiple holograms are recorded with different oblique illumination. All hologram are reconstructed individually using the same program and each reconstructed image has a different speckle pattern. The oblique illumination system is optimized by an automatic two dimensional scanning of the fiber tip. Thus only a limited illumination area of light spot is demanded. By averaging the reconstructed images, the speckle noise of the reconstructed image is reduced. We demonstrate the effectiveness of the technique experimentally. The proposed system is convenient and practical. It can lead to a high quality result automatically.

Techniques for imaging and characterizing magnetic samples have been widely used in many areas of research involving magnetic materials. Nowadays, magnetic microscopy techniques play a critical role in characterizing magnetic thin film structures. In considering the various techniques, optical techniques offer some unique advantages over alternative techniques (e.g. MFM), as they are least affected by magnetic noise and, for the same underlying reasons, have also proven to be more suitable for "high speed" magnetization measurements of magnetization dynamics, which are increasingly important in many of today's research scopes. At the same time, development of metamaterials are opening the doors for newly behaving materials, such as those demonstrating negative refractive index, potentially useful in a variety of applications, such as imaging. Metamaterials deploying arrays of silicon particles, and even alternating silicon particles and split ring resonators have recently been shown to demonstrate interesting behavior, such as negative magnetic susceptibility and large resonant peaks in the Terahertz regime. Such high frequencies offer the potential bandwidth of extraordinarily fast dynamics, which are increasingly being generated in magnetic materials, for example, in optically-induced demagnetization and all-optical magnetic recording. Here, initial investigations toward ultra high-speed imaging and/or information extraction from magnetic samples is discussed considering metamaterials deploying mainly spherical particle arrays. In addition to the frequency spectrums of the system, the response of the system to external magnetic fields and background permeability changes due to external fields are investigated. Our results suggest a significant potential of metamaterials for use in probing information from magnetic materials.

The current development of UV-Blue sensitive photo-detectors has lead to investigations with the polywell-stacked gradient poly-homojunction (StaG) configuration. Backwall illumination is of interest due to increased fill factor and pixel wavelength band tailoring. The StaG architecture has benefits. However, for benefit to backwall illumination the space charge region needs to be depleted to the backwall, possibly dispensing with the need for the StaG multi-layer. This research is an initial investigation of the benefit to crosstalk and sensitivity of the deep single well in high resolution, 5 μm pitch, photodiode arrays. The results indicate that geometries that are of fabricatable morphology can benefit backwall illumination especially in the U/V-blue wavelength spectrum.

In this study, the energy harvester for Bio-MEMS device using a new bio-compatible piezoelectric thin film was developed. At first, we generated MgSiO₃ (MSO) thin film on Ti and Cu buffer layers and Si (100) substrate by using RF-magnetron sputtering procedure. We measured the crystallography orientation by employing the X-ray diffractometer and the piezoelectric properties with the ferroelectric measurement system. We confirmed that MgSiO₃(111) crystal had been generated on Cu/Ti/Si (100) substrate. Its displacement-voltage curve indicated the typical butterfly type hysteresis loop, which meant MgSiO₃(111) thin film had piezoelectricity. The piezoelectric strain constant d33 was calculated by adopting the displacement-voltage curve, such as 181.5 pm/V. Further, the polarization properties of the MSO thin films were measured. The spontaneous polarization and remnant polarization are 0.89 μC/cm² and 1.06 μC/cm². Then, we adopted interdigitated-shape electrodes on MSO film in order to generate the d33 mode of the piezoelectric transducer. Accordingly, the generated voltage was estimated as 3.19 V by employing finite element method, ANSYS. We fabricated a monomorph type MSO piezoelectric cantilever for harvesting the vibration energy by employing the semiconductor process technologies. At last we will show results of performance assessment of our MSO piezoelectric harvester.

A double resonance defected ground structure is proposed as a filter element. The structure involves a transmission line loaded with complementary split ring resonators embedded in a dumbbell shape defected ground structure. By using a parametric study, it is demonstrated that the two resonance frequencies can be independently tuned. Therefore the structure can be used for different applications such as dual bandstop filters and wide bandstop filters.

We use 4,4' azo-bis-(4-cyanopentanoic acid) as chain transfer agent in a photopolymer with triethanolamine/yellowish eosin as initiator system. It is possible to work in a particular conditions to get a chain transfer effect minimizing the decomposition of 4,4' azo-bis-(4-cyanopentanoic acid) by the sensitized dye. The improved photopolymer has a low scattering due to the low molecular weight of the generated polymer chains. This is related to the chain transfer effect in the size of the polymer chains. It is important to establish the optimum concentration of chain transfer agent to avoid decreasing the maximum diffraction efficiency due to a low molecular weight of the polymer chains.

In this study, we present an analysis of optical frequency signal transmission through the whispering gallery mode (WGM) generated in a silica microsphere for the application of optical frequency signal transmission to integrated circuits. The behavior of the WGM within a microsphere was analyzed in detail using the finite-difference time-domain method. The electric field distribution in the silica microsphere led to the WGM, and the electric field was amplified within the microsphere. The interval between the peaks of the WGM (free spectral range of the microcavity) was clearly observed in the wavelength spectrum. When two light beams having slightly different wavelengths were guided into the microsphere, a beat frequency corresponding to the difference frequency of the two light beams was also obtained in the simulation. The simulation results were experimentally confirmed by observing the WGM and the beat signal generated in a silica microsphere. From these results, we have theoretically and experimentally clarified the feasibility of optical frequency signal transmission through the WGM.

Ring of close packed gold nanoparticle arrays offers many fascinating properties that are not found in others assembly patterns. One of the most fantastic features of this unique organization is its ability to reroute shorter wavelengths of light in the visible region of electromagnetic spectrum, making it a very promising nanophotonic components for guiding light at the true nanoscale. Also, the creation of ring with gold nanoparticles can be used to make the world's smallest biosensors possible for multiple disease detection. Herein, we demonstrate a new paradigm for generating rings of CTAB-capped gold nanorods with the implementation of surface acoustic wave (SAW) atomization. With the ultrafast microfluidics actuation, the SAW atomizer can rapidly generate submicron fluids and efficiently form ring arrays onto desired substrates in less than 1s via the evaporative self-assembly process. The technique is able to provide a rational control over the of microfluids size distributions to engineer the smaller monodisperse rings arrays at micrometer scale. This microfluidics-assisted evaporative self assembly approach is also applicable to DNA-capped gold nanoparticles. The non-uniform mass distribution of ring is formed upon the pinning of contact line to substrates during a far-fromequilibrium dewetting process. Our method opens an avenue towards the ring assembly of gold nanoparticles in their ultimate microscopic minimal threshold to facilitate the generation of metamaterials.

Reductions of the obtainable resistivity as well as improvements of the crystallinity in transparent conducting impuritydoped ZnO thin films prepared on low-temperature glass substrates are demonstrated using a newly developed d.c. or r.f. superimposed d.c. magnetron sputtering (dc-MS or rf+dc-MS) deposition technique. The improvements of the obtainable lowest resistivity as well as the crystallinity in Al- and Ga-doped ZnO (AZO and GZO) thin films were achieved by inserting a very thin buffer layer that was deposited using the same d.c. MS apparatus with the same target used to deposit the AZO and GZO thin films. In addition, the insertion of the very thin buffer layer also improved the resulting resistivity distribution on the substrate surface in AZO and GZO thin films. The buffer layer between the thin film and the glass substrate was prepared by dc-MS or rf+dc-MS depositions using a target surface that was more strongly oxidized than usually used during depositions conventionally optimized to obtain lower resistivity; the resulting thin films could exhibit better crystallinity. A resistivity of approximately 3×10^-4 Ωcm was obtained in 150-nm-thick-GZO and -AZO thin films prepared on glass substrates at 200oC.

Multicolor photoluminescence (PL) and electroluminescence (EL) were observed from newly developed Bi- and rare earth (RE)-co-doped (La_1-XGa_X)₂O₃ ((La_1-XGa_X)₂O₃:Bi,RE) phosphor thin films. (La_1-XGa_X)₂O₃:Bi,RE phosphor thin films were prepared by varying the Ga content (Ga/(La+Ga) atomic ratio) or the co-doped RE content (RE/(RE+La+Ga) atomic ratio) under co-doping Bi at a constant content (Bi/(Bi+La+Ga) atomic ratio) of 3 at.% using a combinatorial r.f. magnetron sputtering deposition method. High PL intensity was obtained in postannealed (La_0.9Ga_0.1)₂O₃:Bi,RE phosphor thin films prepared with a Ga content around 10 at.%; TFEL devices fabricated using the phosphor thin films exhibited high luminance. The obtained luminance intensities in EL and PL in the phosphor thin films prepared with various contents of co-doped RE, such as Dy, Er, Eu, Tb and Tm changed considerably as the kind and content of RE were varied. Color changes from blue and blue-green to various colors in PL and EL emissions, respectively, were obtained in postannealed (La_0.9Ga_0.1)₂O₃:Bi,RE phosphor thin films, i.e., films prepared by co-doping Bi at a constant content with various REs at varying levels of content. All the observed emission peaks in PL and EL from (La0_.9Ga_0.1)₂O₃:Bi,RE phosphor thin films were assigned to either the broad emission originating from the transition in Bi³⁺ or the visible emission peaks originating from the transition in the co-doped trivalent RE ion.

Flexible electronic devices rely on effective conductors integrated with elastomeric substrates. This work reports on characterization of thin gold layers on flexible polymers as a platform for further research into their use in flexible electronic and microsystems. This work utilizes standard microfabrication techniques and a biocompatible, silicone polymer (polydimethylsiloxane) as the flexible substrate material. Flexible conductors defined by gold have been realized, and the dependence of resistance on geometry has been characterized. The results follow theoretical resistance dependence on geometry while showing an increase in the resistivity of the gold layer, a direct effect of deposition on elastomer causing wrinkles or striations in the metal layer. This work also discusses the effect of uniaxial mechanical deformation on thin film conductors and defines a procedure for creating and testing them in a repeatable manner. The ability to stretch the resistors by 10%, with full recovery to original resistance value is demonstrated. This work has implications for flexible device performance and provides a platform for integrated applications. Future work will explore combinations with piezoelectric thin films to enable conversion of mechanical to electrical energy, as this flexible platform will enhance the functionality of such energy generators.

The concept of a microfluidic biosensing device based on reflective interferometric spectroscopy (RIfS) is presented in this article. The key element of the sensor is a highly ordered nanoporous structure of anodic aluminium oxide (AAO) integrated into a microfluidic chip combined with an optical fiber spectrophotometer. AAO was prepared by electrochemical anodization of aluminium using 0.3 M oxalic acid. The structural and geometrical features of the AAO porous structures were controlled to provide optimal RIfS sensing characteristics and there sensing capabilities were explored using two different strategies; i) detection based on the response generated by pefusion of analyte ions inside the pores and ii) detection based on specific adsorption of analyte molecules on surface of AAO pores. The second strategy is based on chemical modification of the AAO surface to target molecules based on specific surface binding reactions. In this work two cases are presented, including the binding of small thiol molecules on gold-modified AAO (Au-AAO) and binding of larger targets such as circulating tumour cells (CTC) on antibody-modified AAO. Our preliminary results show an excellent capability of our system in the detection of different analytes using both strategies, and confirm good potential for the development and application of interferometric label-free biosensing devices in a wide range of biomedical applications.

The use of Optical Coherence Tomography (OCT) in early cancer detection is still under development. While the specificity and precision of the technique has improved, the development of affordable, portable OCT configurations is important for increased clinical access by general practitioners. To this end, a proposed microphotonic time domain (TD) OCT system is being developed, based on a liquid crystal array and a microphotonic stepped mirror structure. In order to characterize the practicality of this system and its performance compared to other optical delay line (ODL) and OCT configurations, a previously demonstrated analytical simulation model has now been extended to retrieve from the interferogram, depth profiles and reflectivities for better strata OCT definition. Based on a Michelson interferometer configuration, the model allows user definition of the broadband light source, the sample's characteristics and the ODL configuration. User defined sample characteristics include the number, thickness and reflectivities of layers. The purpose of the forwards model was to compare the conventional moving ODL reference arms with their quasi-stationary and stationary alternatives. The primary goal of the current investigation is to determine the efficacy of the backward fitting model (BFM) that uses a genetic algorithm to iteratively optimize solutions for the layer thickness and layer reflectivities for a given simulated interferogram. The genetic algorithm does retrieve the depth and reflectance of the layers identified in the interferogram, improving in precision and accuracy with each generation. The BFM can deconvolve interferograms produced using different types of ODL, with the prospect of improving the proposed discrete-step quasistationary optical delay line functionality.

This paper presents a method for chemical and biomolecule patterning on planar (2D) surfaces using atmospheric pressure microplasmas. Spatially controlled surface modification is important for the development of emerging technologies such as microfluidic lab-on-a-chip devices, biosensors and other diagnostics tools. A non-fouling layer of poly(N-isopropylacrylamide) aldehyde (pNIPAM-ald) polymer, grafted onto heptylamine plasma polymer (HApp) modified silicon substrates, was used to achieve this goal. The non-fouling behaviour of the pNIPAM-ald coating was investigated at a temperature below its lower critical solution temperature (LCST) using human serum albumin (HSA). XPS and ToF-SIMS were used to characterise the plasma polymer coating and its subsequent modification with pNIPAM-ald before and after HSA adsorption. A 7 x 7 microcavity plasma array device (each cavity had a 250 Νm diameter and was separated by 500 μm) was used for microplasma patterning. In a non-contact mode, helium microplasma treatment of the pNIPAM-ald coating was carried out for 60 s. The polymer coating was removed from regions directly exposed to microplasma cavities, as shown by ToF-SIMS. Microplasma treated regions were able to support the adsorption of fluorescently-labelled streptavidin whereas the rest of the coating was still non-fouling. This approach therefore resulted in spatially separated areas of immobilised protein.

Hybrid nanoporous MCF, SBA-15 and MCM-41 materials were synthesized via hydrothermal treatment and functionalized with 3-aminopropyltriethoxysilane (APTES) via post-synthesis grafting and sequently activated by glutardialdehyde and then were used to immobilize D-amino acid oxidase (DAAO). The amino-functionalized materials were characterized by various techniques: XRD, IR and N₂ adsorption-desorption (BET). From characterization results, it indicated that these materials still maintained their structure after functionalization. The data IR and TGA-DTA analysis demonstrated the incorpotation of amine functional groups on the surface of APTES-functionalized samples. The DAAO immobilized on functionalized materials exhibited higher catalytic activity and stability for conversion of cephalosporin C (CPC) compare to those of non-functionalized one. Further more, the catalytic activity as well as stability of enzyme decreased in order MCF > SBA-15 > MCM-41 with the decrease of their pore size.

We present a set of practical rules critical for designing and building a modern nanotechnology laboratory, focused on photonic applications in a cleanroom environment. We show the impacts on time, cost and quality of early design decisions and its importance on achieving the final fully functional laboratory. Best practice examples are presented for setting up a modern laboratory/facility, following analysis of the time, cost and quality constraints. The case study presented is the engineering and architectural solution of the nanofabrication cleanroom facility in the Advanced Technology Centre at Swinburne University of Technology, Australia. Set of practical rules is established for the cost and time efficient set up of the nanotechnology facilities for the research and development.

This paper reports on the conceptual design and simulation of a new hybrid coupled plasmon/dielectric waveguide device which may present opportunities for biosensing. The operation of the device is based on the phase matching of wave propagation in the dielectric waveguide with that of the surface plasmons. Finite element method (FEM) and eigenmode expansion (EME) methods have been utilised to analyse the characteristics of propagation of these waves. A suitable periodic grating structure has been implemented to provide wavelength dependent phase matching between the dielectric and plasmon modes. The selectivity of plasmon coupling makes it an ideal technology to be utilised for sensing. Such a device may be fabricated as a low cost, highly sensitive, integratable sensor allowing the detection of finite environmental changes including the presence of single layers of molecules.

In the present work, we have prepared functional dye doped TiO2-SiO2 thin films by vertical sedimentation technique. Thin film samples are annealed at different temperature from 50^oC to 850^oC. Morphology and chemical bonding information is analysed using atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR) respectively. Optical properties are characterized by using UV-visible spectroscopy. Effect of annealing temperature on the photonic forbidden band gap is also presented. The experimental measured values are compared with theoretical estimated results.

We present two realizations of a highly sensitive platform useful in environmental sensing and diagnostics - a Fabry-Perot (FP) interferometer - (i) a pair of semi-transparent mirrors integrated into a microfluidic channel and (ii) a silicon membrane of sub-micrometer thickness. Simple way to make microfluidic channels by (i) hot-embossing into a sheet of technical grade PMMA and (ii) double-sided tape fixed glass with Au-coated mirrors are presented. By changing the thickness of the Au coating, the roughness and porosity of mirror surface is controlled. In turn, this provides a method to tune finesse of the FP cavity to monitor solutions flowwing between the FP-mirrors. In case of silicon, the FP cavity is formed by coating two sides of a Si-membrane. These two different approaches to harness a high sensitivity of the FP interferometry are proposed: changes of FP cavity caused by materials in the channel can be monitored, while the coated membrane is used to monitor the effects which are induced by membrane's ambiance. The finesse of the FP cavity is optimized for the maximum spectral sensitivity at the cost of transmitted light intensity in case of microfluidic channel and silicon membrane. Via optimization of the finesse (in the range 2-5) and overall transmission of a FP-pair (20-60%) practical solutions are proposed for spectral sensing of (i) refractive index and mechanical channel width's changes in a microfluidic channel as well as (ii) temperature changes of membrane's environment. Asymmetric thickness of the FP mirrors can be used to optimize sensitivity.

This paper is focused on piezoelectric actuator for precision stage system which has nano-scale resolution. Nanometer order positioning techniques are necessary for semiconductor manufacturing and its inspection. For these demands, we propose the nonresonant-ultrasonic motor(NRUSM) as driving source of positioning stage. One can use as the stage driving device in a SEM chamber, because NRUSM is non-magnetic device. In addition NRUSM is able to be made compact, can be equipped at various miniature tools, for instance, manipulation, pumping, probing systems, having nano scale resolution. NRUSM is also adopted to Reticle Free Exposure system which can make the flexible patterning by fine displacing of mask patterns. NRUSM's weak point is the occurrence of a wear because of friction caused by the ultrasonic motor. However this wear can be cut down by reducing the slipping. A previously proven effective solution, by which the driving keeps in the range of static friction without the slipping, results in long life time, high-durability and decrease of particles. We propose two solutions to reduce the slipping: driving method and change of structure. The former is control method using variable frequency instead of constant frequency. The latter is increase of friction tips because static frictional force is proportional to number of the tips.

Polymeric coatings which allow the effective control of biointerfacial interactions and cellular responses are of increasing interest in a range of biomedical applications in vitro and in vivo such as cell culture tools, biosensors and implantable medical devices. A variety of coating strategies have been developed to gain control over cell-surface interactions but many of them are limited with respect to their function and transferability between different substrate materials. Here, our aim was to establish an easily transferable coating that reduces non-specific cell-surface interactions to a minimum while at the same time presenting functional groups which allow for the subsequent immobilisation of bioactive signals. To achieve this, we have applied an allylamine plasma polymer coating followed by the covalent immobilisation of a macro-initiator providing iniferter functional groups. Subsequent controlled free radical graft polymerisation using the monomers acrylamide and acrylic acid in different molar ratios resulted in highly uniform polymer coatings. Non-specific cell attachment was significantly reduced on coatings representing molar ratios of less than 10% acylic acid. At the same time, we have demonstrated the suitability of these coatings for the subsequent covalent binding of bioactive compounds carrying amine functional groups using the label 2,2,2-trifluoroethylamine. Successful surface modifications were confirmed by X-ray photoelectron spectroscopy (XPS) and profilometry. The cellular response was evaluated using HeLa cell attachment experiments for up to 24 hours. We expect that the coating platform established in this study will be translated into a number of biomedical applications, including applications in implantable devices and regenerative medicine.

A variety of microscopy techniques allow measuring different local physical properties of a surface under test. One of the key properties of interest in production and development of micro- and nano components is a nanometer resolution even in a measurement range of a few centimeters. By integrating a low coherent digital holographic microscope (DHM) into a coordinate measuring machine with sub nanometer resolution and nanometer uncertainty, a DHM with an outstanding measuring range is realized which enables simultaneous investigation of form and roughness of specimens with sizes up to 25 mm×25 mm×5mm along the x, y and z-axes. Different modes of scanning strategies have been analyzed and error compensated for micro and nano structured optical components with a surface diameter up to 25mm. For calculation of the correlation and thus effective coherence length, which is used for analysis of the topography of the specimen, a comprehensive theoretical approach is demonstrated and experimentally verified.

This paper demonstrates the structural optimization using Evolutionary Algorithms in a chalcogenide glass waveguide. Four features are taken into consideration while optimizing the waveguide structure, they include: single-mode, low dispersion, high nonlinearity and low loss. A set of waveguide structures which meet the design criteria are shown in the paper. The best structure enhances the nonlinear coefficient to 26000 /W/km at telecom wavelength. In this work, we demonstrate the methodology used to optimize waveguide as well as the procedure of conducting the experiment.