The light reflectance in 3-dimensional metal-dielectric photonic crystals, assembled from polyelectrolyte-coated latex spheres and infiltrated after opal crystallisation with gold nanoparticles, has been studied. Development of the surface plasmon resonance bands of Au nanoshells along the increase of the Au nanoparticle concentration has also been observed, along with deviation of the diffraction resonance dispersion and formation of the specific excitation, which combines photonic crystal optical mode with surface plasmon resonance. For heavy nanoparticle loadings, the reentrant dielectric type behaviour of the metal-dielectric photonic crystal has been seen.

Scaling photonics devices in silicon on insulator (SOI) substrates has the potential to address important issues in the fields of optical telecommunications and optical interconnects. Silicon, is highly transparent in the infra-red spectral region and etching ribs or rectangular channels can create the condition for single-mode low-loss waveguiding. The high index difference between silicon and the surrounding media, typically SiO2 or air, is extremely favorable for the development of ultra-compact photonic devices. Active functionality can be performed by free charge injection in the waveguide resulting in a phase shift of the propagating fundamental mode. Moreover this technology is fully CMOS compatible allowing a low-cost monolithic integration of control electronics. Limitations deriving from an aggressive scaling of SOI waveguides are a lowered efficiency in the in-out coupling of light and higher propagation losses due to increased roughness scattering. We report on the perspectives and issues of scaling SOI photonics devices for both passive and active functionality. Results show that scaled waveguides can have very low bending radii down to the micrometer range. We also propose a new method and architecture for light phase modulation based on a Schottky barrier diode; a process flow will be analyzed and validated experimentally.

A number of modern techniques for microelectronics, microoptics, optoelectronics, and micromechanics are required the lithography of objects presented big arrays of nanoscale structures of the complicated form. The electron beam lithography tools with Gaussian vector scan beam and the projection electron lithography systems (SCALPEL and LEEPL), having a few nanometers resolution, good flexibility, and large work field, have a good outlook for creation of devices of this class. Only the first may be used for direct writing. But the writing speed may decrease dramatically with reducing of beam diameter d as d^-6 in some case. Increasing the resolution of electron beam-resist system and the throughput are the important problems in this case. The paper is directed on development of theory and strategy of electron beam lithography for its application in the nanometer length scale. The achievements of electron beam lithography are compared with success in the field of optical and x-ray lithography.

The electrical properties of C60 have been extensively studied in both the solid and solution phases. The vibrational spectroscopy of C60 is predominantly molecular in character. However electronic spectroscopy reveals features, which are specific to the solid. These features have been attributed to intermolecular charge transfer states. The relative importance of these inter- and intramolecular processes in terms of their contribution to the electronic transport is discussed. Cyclic voltammetry is employed to generate charged molecular species, which also contribute to the conduction process and comparisons to optical excited states species are drawn. The cyclic voltammetry was monitored in situ with vibrational spectroscopy so as to observe any shifts in the C₆₀ spectrum due to charging. The current voltage characteristics of thin film sandwich structures fabricated by vacuum are then presented and discussed. A strongly non-linear behaviour is observed, a sharp increase in the device conductance being observed at relatively low voltages at both room temperature and at 20K. The room temperature IV curves confirm a lattice collapse upon charging. The high conductivity state is however observed to be stable at low temperature.

Single-wall carbon nanotubes (SWCNT) are severely restricted in their applications, as they exist in rope-like bundles. Recently, J. Coleman et al. demonstrated a spectroscopic method to monitor bundle dissociation in low concentration NT-polymer composites. The method relies on the measurement of the ratio of free-polymer to the nanotube-bound polymer in the SWCNT-polymer solutions via luminescent spectroscopy. A theory has been developed to transform this data into the bundle surface area, which is of course related to the bundle size. This method clearly shows that individual, isolated SWCNT are stable in low concentration dispersions. The main aim of this work is to better understanding of the physics behind polymer-SWCNT interactions, the binding scheme, and the magnitude of the polymer-SWCNT binding energy. In an effort to broaden the understanding of the physical processes governing the NT de-bundling a wide range of suitable polymers and short-chain molecules have been examined. We found a strong dependence of the concentration at which individual NTs become stable with the nature of the dispersant molecule.

We present changes in the first and second order Raman spectra of multi-walled carbon nanotubes (MWNTs) induced by wet chemical methods. The MWNTs studied were initially treated in HCl to remove the metal growth catalyst and subsequently were subjected to two acid purification routes: 1) reflux in HNO₃ acid and 2) ultrasonification in 3 HNO₃ :1H₂SO₄. Raman spectroscopy, using two laser excitation wavelengths (514.5 and 632.8 nm) and XPS were employed to study the evolution of the products. XPS analysis confirmed the presence of oxygen functionalities and electron extraction phenomena. Charge transfer phenomena were observed by a shift of the C1s core level towards higher binding energies. We found that the intensity of both the D and G energy Raman modes if normalized to the second order mode D* mode follow similar trends upon acid treatments. We interpret this result together with the observed dispersion of G mode as an indication that the G mode in carbon nanotubes is defect induced, in a double resonant process. Both acid schemes cause an up-shift of D and G Raman modes, due to intercalation of acid molecules, exerting pressure on the sp² structure and an electron transfer from the p states in MWNTs to the oxygen atoms.

Arrays of interconnect-type carbon nanotubes (CNTs) have been grown over etched silicon substrates. These tubes are grown over trenches ranging from 200-1000 nm in width. Through control of initial parameters such as trench size, catalyst concentration and the initial parameters for the chemical vapour deposition (CVD) of the tubes (gas flow rates, gas flow times and reaction temperature) dense arrays of CNTs spanning the trenches have been formed, with densities in the region of 1.6 interconnects per micron of trench length. High proportions of branch-structure CNTs have been noted within these arrays. The cleaved sections of silicon substrate are simply treated by drop-casting and drying catalyst-containing solution prior to CVD treatment. The density of the resultant arrays can be controlled through the density of the catalyst solution.

In this study CdTe quantum dots have been successfully prepared in aqueous medium using several different thiol stabilizers. The resulting nanocrystals were purified and the photoluminescence efficiency was subsequently enhanced through post preparative procedures such as photochemical etching and ageing. An optical study was carried out on the resulting CdTe nanocrystals as proof as their improvement. Preliminary tests of the thiol stabilised QDs as potential biolabels have been performed. It has been shown that L-cysteine stabilised QDs localising to the outer cell membrane in living cells. TGA stabilised CdTe QDs can potentially serve as live cell imaging tools as they exhibit strong luminescence and excellent photostability. In addition, the ability of TGA stabilised CdTe QDs to traverse the cell membrane of macrophages is a formidable quality that may potentially be harnessed for imaging and therapeutics. Modulating the delivery of QDs to subcellular locations in living cells opens a myriad of potential applications ranging from drug delivery to examination of intracellular processes.

In this paper, we report on a strategy, which produces enhancement of fluorescence using the so-called plasmonic effect whereby the presence of adjacent metallic nanoparticles can dramatically alter the fluorescence emission and absorption properties of a fluorophore. The effect, which is a result of the surface plasmon resonance of the metal surface, can lead to increases in quantum efficiency, radiative decay rates and photostability of the fluorophore, and depends very sensitively on parameters such as geometry of the nanoparticles, nanoparticle-fluorophore separation and fluorophore type. The work is aimed at improving the efficiency of optical biochips. Key benefits from this enhancement include lower limits of detection, reduced reagent requirements and better resolution. This study is part of a comprehensive investigation of plasmonic enhancement using a range of metal nanoparticle (NP) fabrication techniques and a range of measurement configurations. The focus here is on the fabrication of chemically prepared silver-gold alloy spherical NP with a variable thickness silica shell on the surface of which is immobilised a layer of fluorescent dye molecules. The variable thickness shell serves to control the dye-NP separation, which plays a key role in the enhancement mechanism. Transmission electron microscopy (TEM) was used to characterise the NP. The dye used here was the ruthenium polypyridyl complex [Ru(II)-tris(4,7-diphenyl-1,10-phenanthroline)], abbreviated to [Ru(dpp)₃]²⁺. This paper reports the tuning of the NP plasmon resonance via NP size and alloy composition. The wavelength of the plasmon peak as a function of NP size and composition correlated very well with theoretical predictions based on the Mie scattering theory. Preliminary fluorescence enhancement measurements on this system yielded an enhancement factor of approximately 5.

Spectroscopic measurements have been undertaken for a range of different quantum dot (QD) types and transparent host materials for use in a novel solar energy-concentrating device, a Quantum Dot Solar Concentrator1 (QDSC). A QDSC comprises QDs seeded in materials such as plastics and glasses that are suitable for incorporation into buildings where photovoltaic cells attached to the edges convert direct and diffuse solar energy into electricity for use in the building. High transparency in the matrix material and QDs with a large Stokes shift are essential for an efficient QDSC. An optimum matrix material for a QDSC has been determined based on absorption characteristics and an optimum commercially available QD type has been chosen using steady-state absorption, photoluminescence and photoluminescence excitation spectroscopy of QDs in solution and solid matrices.

Reported is the use of DNA to template the assembly of nanowires and protein-functionalized nanogap electrodes. Specifically, the use of DNA to template the assembly of gold nanowires between conventionally patterned gold contacts on a silicon wafer substrate. Also the use of DNA to template the assembly of protein-functionalized gold nanogap electrodes on a silicon wafer substrate. Of particular significance is the finding that suitably modified gold nanoparticles recognize and bind selectively the protein-functionalized nanogap between the above electrodes and are localized there. This and related work forms part of a broader effort directed toward the development of the alternative bottom-up fabrication technologies that will be needed to extend Moore's Law beyond 2012.

The processing of most one-dimensional nano-materials such as carbon-nanotubes is hampered by the fact that they are insoluble. Here we show how a significant portion (≈12wt%) of the as-produced Mo₆S_4.5I_4.5 nanowires is stably dispersed in isopropanol as small diameter nanowire bundles. Sedimentation studies, performed combining experiments and theory, show the presence of three phases in the raw material: impurity material, insoluble and soluble nanowire bundles. A purification procedure is also discussed. The three phases has been characterized by UV-Vix-IR spectroscopy and XPS showing their intrinsic diversity.

In real electronic devices the elevated operating temperature of the active medium with respect to the "standard" room temperature (21-23°C) is a direct result of Joule heating and acts as a limiter to device performance and lifetime. It has been shown for discrete devices that as the active area is reduced the device is less susceptible to Joule heating. Therefore smaller devices may be driven at higher current densities for a longer period of time than similar devices with a larger active area. This is important for electronic display applications where the display brightness, which is proportional to current density and the display lifetime, is critical. We report on how a porous alumina membrane, filled with nickel using a pulsed electro-deposition technique, was used as a nano-structured anode in polymer light-emitting diodes. Devices made using mechanically polished nickel-filled membranes were tested. Electrical data are presented and the uniformly filled porous alumina based devices sustained higher current densities, than equivalent conventional evaporated metallic sheet-electrode devices. It was found that the reproducibility and rectification ratios of the uniformly filled nickel devices represent a significant improvement on similar copper-filled devices.

We present details on the CdTe nanowires formation, which were found to grow in a standard physiological phosphate-buffered solution, including in-situ observation of growth with a confocal microscope. The choice of proper nanocrystals concentration allowed reasonably slow growth rates and thus a controllable formation of nanowires. Once formed in solution, nanowires showed a significant degree of structural rigidity and resistance to externally applied mechanical stress. Luminescence and Raman spectroscopy data evidence on re-crystallization processes during the nanowire formation.

We report the synthesis of silver nanoparticles by laser ablation of the bulk material in water and five other organic solvents employing a frequency doubled Nd:YAG laser at 532 nm. The colloidal suspensions were characterized by means of UV/VIS absorption spectroscopy and transmission electron microscopy. The reproducibility of the particles' size distribution and yield, which strongly depends on the solvent and the ablation condition, is critically reviewed. The agglomeration behaviour of silver particles was investigated as a function of temperature. The unusual role of water in the ablation process and upon agglomeration will be discussed.

Tailored pore size mesoporous silica, incorporating different concentrations of transition metal-based catalysts, has been used as platforms for the growth of carbon nanotubes by the catalytic chemical vapor deposition method. Both compositional surface analysis by EDX/SEM combinatory techniques and thermo gravimetric analysis were employed to characterize the samples prior to CNT growth. The CNTs produced were characterized using Raman Spectroscopy, high resolution SEM and TEM. Raman spectroscopy showed good quality highly graphitic CNTs and indicated the presence of crystalline graphitic carbon, microcrystalline graphite as well as amorphous carbon in the carbon nanotube layer. TEM and HI RES SEM images matched diameters of the carbon nanotubes to the corresponding pores of the matrices. Comparison of the carbon nanotube diameters to porous properties of the mesoporous silica confirmed probable growth from within the pores. The density of the carbon nanotubes was found to be high for higher metal concentrations for the same pore diameters. Fe and Co were confirmed to be better catalysts, compared to Ni, for growth of carbon nanotubes by the catalytic chemical vapour method.

Transparent polycrystalline diamond films with grain size ranging from a few tens to hundreds of nanometres were prepared on fused silica substrate by Microwave Chemical Plasma Vapour Deposition method (MPCVD). The new technique, called alternating nanodiamonds injection, was applied for substrate pretreatment. It was demonstrated that nanodiamonds injected on fused silica substrate serve as nucleation centres and make possible an increase in nucleation density to 10¹⁰ cm^-2. The influence of MPCVD parameters such as methane concentration, total pressure and substrate temperature on the crystalline structure and optical properties of diamond films were investigated by using micro-Raman spectroscopy and scanning electron microscopy, transmittance and reflectance measurements in the wavelength range of 400-1000 nm. Under appropriate MPCVD parameters, diamond films with optical transmission ~70% from 650 to 1000 nm and high content of diamond phase were fabricated.

Magnetite nanoparticles have been coated by a porphyrin derivative to produce new magnetic materials with fluorescent properties. The magnetic nanoparticles were prepared using two different methods, one based on sol-gel techniques and ultrasonic processing, and the other via a controlled chemical co-precipitation. Different types of porphyrin functionalised magnetic nanoparticles have been prepared and have been characterised by electron microscopy (TEM and SEM), XRD, FTIR, Raman, UV-vis, and fluorescence spectroscopy. Microscopy results showed the formation of core-shell nanostructures, with IR and photoluminescence spectroscopy results confirming the presence of porphyrin in the shell.

We report the integration of phase gratings directly onto the surface of red vertical cavity surface emitting lasers (VCSELs) by Focused Ion Beam etching. Gratings have been used to generate quasi Bessel beams. The fabricated devices show that a diffraction limited central spot can be formed above the surface of the device. The narrow spot has a full width at half maximum of 0.5μm at a distance of 2μm above the VCSEL surface. The compact device can be formed in arrays and can be considered for a large number of sensing applications such as an optical probe for biophotonics and in optical recording systems.

In this study, Strained silicon Quantum Wells (QW) were characterised using a variety of micro-scopical techniques. Among the techniques used were Transmission Electron Microscopy (TEM), Elemental Electron Loss Spectroscopy (EELS), and micro-Raman spectroscopy. A combination of these methods facilitates investigation of the structure, the strain, and the dislocations present in such materials. Both conventional and High Resolution Transmission Electron Microscopy (HRTEM) are used to analyse strained silicon quantum wells (QW). These techniques allow for structure analysis at the atomic level. Elemental Electron Loss Spectroscopy (EELS) is used in tandem with other analytical techniques in order to give a quantitative analysis of the structures. The presence of various layers is independently verified using EELS, while layer depth and concentration profiles are also established. Relaxation levels in the virtual substrate as well as the strain in Si quantum wells are calculated using Raman spectroscopy.

The interaction of carbon nanotubes with soft organic molecules such as cyclodextrins and other saccharides has recently been shown to produce water-soluble composites. Such systems offer considerable advantages over polymer based composites due to their biocompatibility and non-covalent coupling which can potentially preserve the unique properties of the tubes. The mechanism of interaction of such systems has been proposed to be dominated by hydrophobic and hydrophilic interactions along the surface of the tube. In this study a number of composite systems have been formed with HiPco carbon nanotubes using starch.

Improvements to the immobilisation of bio-recognition elements to sensor surfaces are keenly sought. Surface Plasmon Resonance is a highly sensitive optical based sensing technique that is being used in this research as a means of evaluating novel immobilisation techniques. We report on the establishment of binding-sites at the sensor surface using two diverse methods. In the first method, well established deposition techniques were used to coat the gold surface with a silicon rich matrix. It is demonstrated that control of the depth of the material to within 10 nm was achieved. In a second method highly ordered arrays of genetically modified biological materials have been used to form attachment sites and are being investigated. Careful choice of amino acid placement at the apical domain could provide bio-selective attachment, with control in three dimensions in the region of 10's of nanometres. Characterisation of the active surfaces in each instance is presented using a number of well established techniques such as Scanning Electron Microscopy, Raman, Profilometry and Atomic Force Microscopy. Investigations, although at an early stage, have shown promise. Initial results obtained for sensitivity to glucose are indicative of an overall improvement over conventional techniques taking into account the key aspects of metal layer thickness and penetration depth of the surface plasmon wave.

The adsorption properties of polymers are of great importance for implant studies. A better understanding of these properties can lead to improved implant materials. In this study the surface energy of different polymers was derived from contact angle measurements taken using profile analysis tensiometry (PAT) of sessile drops of water. The contact angles were measured for advancing and receding water drops on polished polymer surfaces and also on polymer surfaces modified by adsorbing protein to the surface prior to analysis of the sessile drop. The protein used was bovine serum albumin (BSA) and the surfaces were poly-methylmethacrylate (PMMA), poly-ether-ether-ketone (PEEK) and stainless steel. The polymer surfaces were also studied using atomic force microscopy (AFM). Images of the surfaces were taken in different states: rough, smooth and with albumin adsorbed. As a method to identify the proteins on the surface easier, anti-albumin antibodies with 30nm nano gold particles attached were adsorbed to the albumin on the surfaces. Using nano gold particles made the imaging more straightforward and thus made identification of the protein on the surface easier. The results from this work show the differing hydrophobicities of polymer surfaces under different conditions and a new nanotechnological method of protein identification.

This paper presents a comprehensive list of issues related to the electrical characteristics of both electrostatic and electromagnetic micromotors and aims at understanding the behavior of the micromotor from the electrical standpoint. The paper takes the step-by-step approach by first presenting an overview of the laws of electrostatics and electromagnetism for micromachines, their applicability, features and limitations, and then progresses to independently analyze some of the important machine related quantities like electromotive torque, force-output, angular frequencies, supply conditions and requirements, for different types of electrostatic and electromagnetic micromotor constructions. A thorough study on the electric machine parameters that affect the performance of the micromotor need to be performed, since it would serve as a useful link in integrating the micromachine output performance with the fabrication process and challenges associated with it. Achieving such integration would then determine the optimized working condition for the micromotor. The main reason for this study is that although significant advancements have fostered the growth of micromotors in the recent past which has led to the establishment of the micromotor as quite a remarkable machine for powering micromechanical devices, and also as an industrial requirement for various applications, there has always been a concern about the optimal performance of the micromotor, since there is more than just one technology that is being incorporated to realize the micromotor. With fields ranging from surface engineering and chemistry to material science engineering exerting influence on the micromotor design, it becomes very important to completely comprehend the electrophysics of the micromachine that would in turn interact with the science of fabrication to result in the development of better micromotors with considerably less functional complexity.

This paper describes an innovative excimer laser fabrication approach for profiling optimally smooth airflow contours. The research merit of the process is its use in producing a new type of electrical transducer micro-turbine using a novel axial format. The necessary micro-machining precision for this was achieved by computer-controlling a laser beam using an elevating stage to step a moving mask across a fixed mask, i.e. a variant of dynamic mask-dragging or mask-aperturing. The moving mask image was projected on to a series of flat 600 μm wide, 1000 μm deep preform surfaces, reducing each to 50 μm thickness with curvature. Precise control of each mask increment to ablation depth and focus allowed a range of 3-D curves to be realized. The ablation rate versus surface quality was optimized throughout by ablating just 300 nm per laser pulse and using 2000 pulses spread over 90 sites. The process represents a cost effective means of using basic masks to continuously shape flat surfaces in the axial direction with high aspect ratios, high speed and precision, and is applicable to both micro streamlining and the manufacture of micro expansion nozzles.

Nano-particles play not only a key role in recent research fields, but also in the public discussions about health and safety in nanotechnology. Nevertheless, the worldwide activities in nano-particles research increased dramatically during the last 5 to 10 years. There are different potential routes for the future production of nano-particles at large scale. The main directions envisaged are mechanical milling, wet chemical reactions or gas phase processes. Each of the processes has its specific advantages and limitations. Mechanical milling and wet chemical reactions are typically time intensive and batch processes, whereas gas phase productions by flames or plasma can be carried out continuously. Materials of interest are mainly oxide ceramics, carbides, nitrides, and pure metals. Nano-ceramics are interesting candidates for coating technologies due to expected higher coating toughness, better thermal shock and wear resistance. Especially embedded nano-carbides and-nitrides offer homogenously distributed hard phases, which enhance coatings hardness. Thermal spraying, a nearly 100 years old and world wide established coating technology, gets new possibilities thanks to optimized, nano-sized and/or nano-structured powders. Latest coating system developments like high velocity flame spraying (HVOF), cold gas deposition or liquid suspension spraying in combination with new powder qualities may open new applications and markets. This article gives an overview on the latest activities in nano-particle research and production in special relation to thermal spray coating technology.

In recent past, research has been broadly based on controlling matter at nanometer scale, and this idea led to the development of new materials with unique and useful properties. Thus, the implementation of new technology has so far made possible many small-scale power electronic circuits and elements, which are widely being used, in various commercial applications. Nano power electronics is a developing field, where the circuitry is composed of molecular dimensional power electronic components, which includes all types of power switches and devices. The area of nano power electronics have recently been the most intensive area of concentration for researchers of all fields like material science, biotechnology, physics, chemistry, and all engineering fields. Nano scale electronics would define the latest advancements in the solid-state device technology; to make nanometer dimensional FET and MOSFET switches operate for molecular scale circuits and devices. Micro and nano scale electromechanical systems which function with many nano scale elements inbuilt within them, are very useful for different purposes in medical science and many other areas.

Thermal sprayed coatings have wide engineering applications. There now exists a wide range of destructive and nondestructive testing (NDT) methods for surface coating inspections. This paper describes an application of Electronic Speckle Pattern Shearing Interferometry (ESPSI) for NDT of thermal sprayed surface coatings. In contrast to other conventional methods such as eddy current, ultrasonic or X-ray, ESPSI allows fast and large survey area inspection. Experimental results of shearographic measurements are presented. Thermal sprayed coatings were tested using ESPSI. Delaminations of the coatings were detected and the fringe patterns were captured using this method. It is shown that the shearography technique can be applied successfully to surface coating quality inspection and it is very effective for delamination detection.

The paper presents a model of a novel miniature piezoelectric motor (MPM) that produces rotation at versatile torque and speeds. This is a disk type motor that provides actuation to nano- and micromachines. The MPM relies on the piezoelectric effect rather than the magnetic field phenomenon to produce rotation, and hence, it is well suited for applications where a magnetic field is not tolerated and in miniature sizes (possibly nano sizes in the near future, as the author is working on a new nanomanufacturing technique which will facilitate the fabrication of structures at the nanoscale.). In addition to its small size compared with magnetic motors, the MPM can be activated with low voltage, because it converts the electrical energy directly into motion. For this reason, MPM can achieve nano-scale precision when used in positioning applications. Initial simulation results of the proposed model have affirmed that the MPM can deliver large torque compared with some commercial micro motors, and consumes less electrical energy. One point is highlighted in the results is the suitability of the motor to applications that require large torque rather than speed. Besides that, a significant feature of the micro motor is its thickness. Because the motor has no length as in traditional micro motors, it can be used as a disk motor in applications where the available free space is limited to the motor diameter.

This paper is a roadmap to the exhaustive role of the newly emerging field of nanotechnology in various application and research areas. Some of the today's important topics are plasma, dielectric layer semiconductor, and carbon nanoparticle based technologies. Carbon nanotubes are very useful for the purpose of fabricating nano opto power devices. The basic concept behind tunneling of electrons has been utilized to define another scope of this technology, and thus came many quantum scale tunneling devices and elements. Fabrication of crystal semiconductors of high quality along with oxides of nano aspect would give rise to superior device performance and find applications such as LEDs, LASER, VLSI technology and also in highly efficient solar cells. Many nano-research based organizations are fully devoted to develop nano power cells, which would give birth to new battery cells, tunneling devises, with high power quality, longer lives, and higher activation rates. Different electronics industries as well as the military organizations would be largely benefited due to this major component and system design ideas of 'Smart Power' technologies. The contribution of nano scale power electronics would be realized in various fields like switching devices, electromechanical systems and quantum science. Such a sophisticated technology will have great impact on the modernization of robotics; space systems, automotive systems and many other fields. The highly emerging field of nanomedicine according to specialists would bring a dramatic revolution in the present century. However nanomedicine is nothing but an integration of biology, medicine and technology. Thermoelectric materials as been referred earlier also are used in case of implantable medical equipments for generation of electric power sufficient for those equipments.

Lateral growth of ZnO nanowall arrays with subsequent growth of vertical nanowires using a two-step vapour phase transport method on a-plane sapphire are reported. X-ray diffraction and scanning electron microscopy data show that the nanostructures are aligned with c-axis normal to the substrate. Photoluminescence data demonstrate the exceptionally high optical quality of these structures, with intense emission and narrow bound exciton linewidths. We observe high energy excitonic emission at low temperatures close to the band-edge which we assign to the surface exciton in ZnO at ~3.366 eV. This assignment is consistent with the large surface to volume ratio of the nanowire systems and indicates that this large ratio has a significant effect on the luminescence even at low temperatures. The band-edge intensity decays rapidly with increasing temperature compared to bulk single crystal material, indicating a strong temperature-activated non-radiative mechanism peculiar to the nanostructures. No evidence is seen of the free exciton emission due to exciton delocalisation in the nanostructures with increased temperature, unlike the behaviour in bulk material. The use of such nanostructures in room temperature optoelectronic devices appears to be dependent on the control or elimination of such surface effects.

The requirements of optical surfaces are increasing with respect to their functionality and accuracy of form. Furthermore, it is a goal for the optical industry to unify the lens process from development to production. In our phase of design we have an arbitrary set of 3D-points of a free formed surface. With approximation through NURBS, we get a continuous description of this surface. To the generated NURB-Spline, we have developed a CNC-program for the UPM-3000 machine, which drives the cutter along the level curve. Therefore, we triangulate the NURBS-surface. By the desired accuracy and the generated triangles, we determine levels of the surface. Thus, we refine the given triangulation. Hence we have a triangular decomposition for each level, which will be driven along by the cutter. The described method will be compared to the common raster-fly-cut-method for accuracy and cutting time.

Hybrid organic-inorganic materials based on the sol-gel synthesis of organically modified silicon alkoxides have demonstrated their great potential for optical applications. They offer a high versatility in terms of chemical, physical properties and macroscopic shape molding of the final component. In a first step, hydrolysis and condensation reactions are led along the same way as in classical sol-gel glasses. Partial elaboration of the silicate backbone is thus achieved. Then, free-radical polymerization is proceeded by irradiating the sample under UV or visible light. Finally, the material consists of two crosslinked inorganic and organic networks that are interpenetrated. The present paper focuses on a photolithographic process allowing the generation of relief optical elements without requiring a wet treatment to reveal the latent image. It enables a low cost, simple and quick method for the fabrication of integrated micro-optical components with a spatial frequency up to 250 l/mm. The aim of the present work is to give particular attention to the kinetic aspects of the polymerization of the organic component. The control of the C=C double bonds conversion of acrylate functionalized alkoxides in case of photopolymerization is therefore, an essential issue to tailor material properties. The study also focuses on the influence of physico-chemical parameters that govern the relief generation. Kinetics of surface corrugation point out the importance of strain relaxation, mass-transfer by flowing and organic network formation during the photolithographic process. Some illustrations of the generated diffraction gratings are given.

Neutron techniques, among the other non-destructive diagnostics, are becoming more and more relevant in investigating materials and components of industrial interest. In this paper, Small Angle Neutron Scattering (SANS) for microstructural characterisation-especially related to the nanoscale-and Neutron Diffraction for Residual Stresses (RS) measurements are considered. The basic theoretical aspects and some industrial applications of each technique are described. In particular, RS determination in welding, in extruded specimens and in components for energy industry is reported. SANS measurements concerning materials and components for energy and automotive industry are finally presented.

PP-based nanocomposite fibres were prepared by direct polymer melt intercalation. With the intention to determine the size and dispersion of nanoparticles in the polymer matrix, fibres were plasma etched and SEM observations were performed. The influence of nanofiller content and coupling agent on electrokinetic properties was studied. PP monofilament fibres exhibit hydrophobe character with negative zeta potential value. The zeta potential value of co-polymer PP fibre decreases with increasing PPAA content and the isoelectric point IEP of co-polymer samples shifts towards acid region. Addition of modified montmorillonite due to the particles electropositive character, affects the reduction of zeta potential value and a slight shift of IEP towards neutral region is observed. Nano-particles content influences electrokinetic fibres properties, i.e. ZP value is changed, however IE point is not significantly changed by different concentrations of nanofiller. In addition to, mechanical properties of nanocomposite fibres were determined.