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The purpose of the present study is to deepen our knowledge about the painting materials and technology characteristics of iconography during the Bulgarian National Revival. Our efforts have focused on studying the murals in the catholicon (main church) "The Nativity of the Virgin" of the Rila Monastery, which is one of Bulgarian leading historical monuments. A series of micro samples from the altar mural paintings were analyzed by a combination of attenuated total reflectance Fourier transform infrared (ATR-FTIR), micro-Raman spectroscopy, scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Optical microscopy (OM). The data analysis showed that the painter's palette is made up of nine mineral pigments: smalt, chrome yellow, emerald green, vermilion, red lead, green earths, yellow ochre, sienna and calcite. The impression of rich colorful palette was achieved by using various pigment mixtures. The presence of egg binder in many paint samples suggested that the murals were executed by the traditional egg tempera technique, with the only exception of the smalt paint of the background where carbohydrate glue is present as binder.

Support wettability can play a key role in directing the activation of oxygen during catalytic wet air oxidation over nanoparticle catalysts. When the nanoparticles are composed of metallic Pt, the optimum support is hydrophobic, but when they are ionic Ru, a hydrophilic support is more effective. This reversal in support effect is consistent with two distinct surface pathways: one in which gas-phase O2 is directly adsorbed on the Pt0 surface and the other in which dissolved O2 is activated on RuO2 immersed in the contaminated aqueous phase. The known effects of ceria on these precious metal catalysts are of secondary importance to support wettability.

A profound study of samples obtained from Thracian tomb wall paintings at Alexandrovo, Bulgaria (dating back to the fourth century BC) were carried out by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and Attenuated Total Reflectance Fourier transform infrared spectroscopy (ATR FTIR), high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS). The current work provides a glimpse of the ingenious construction and painting techniques used in Thracian tomb at Alexandrovo. The results suggest that beeswax was used as a paint binder and also revealed presence of various nano-materials.

Nanostructured tin dioxide materials (nano-SnO2-A and nano-SnO2-B) were prepared using various tin precursors. They possess high specific surface areas due to their particle sizes and pore size distributions in the nanoscale. These materials were used as supports for lipases and for the preparation of nanocomposite catalysts that can be utilized in various environmentally beneficial processes. The obtained Pd- or Pt-containing catalysts were studied in the total oxidation of ethyl acetate reaction. The results showed that only a small amount (1 wt.%) of highly and homogeneously dispersed Pd or Pt additive is sufficient to improve and substantially decrease the temperature (with about 100 K) of total oxidation ability of the initial nanostructured SnO2 materials, which makes them very promising catalysts for elimination of volatile organic compounds. The material with the higher specific surface area (170 m2/g), nano-SnO2-A, was used as support for lipases from Candida rugosa, porcine pancreas and Rhizopus delemar (resp., nano-SnO2-A-CRL, nano-SnO2-A-PPL, nano-SnO2-A-RhDL). Nano-SnO2-A-RhDL exhibited up to 150-fold higher specific activity than the same enzyme adsorbed on silica. The synthetic activity and stability of the three biocatalysts were evaluated in multiple runs of synthesis of the banana flavor ester, an aroma widely used in food, pharmaceutical and detergent industries.

High quality CuS and CuS/ZnS core/shell nanocrystals (NCs) were synthesized in a large quantity using a facile hydrothermal method at low temperatures of 60 C and evaluated in the photodegradation of Rhodamine B (RhB) under visible light irradiation. Synthesis time plays an important role in controlling the morphology, size and photocatalytic activity of both CuS and CuS/ZnS core/shell NCs which evolve from spherical shaped particles to form rods with increasing reaction time, and after 5 h resemble "flower" shaped morphologies in which each "flower" is composed of many NCs. Photocatalytic activity originates from photo-generated holes in the narrow bandgap CuS, with encapsulation by large bandgap ZnS layers used to form the core/shell structure that improves the resistance of CuS towards photocorrosion. Such CuS/ZnS core/shell structures exhibit much higher photocatalytic activity than CuS or ZnS NCs alone under visible light illumination, and is attributed to higher charge separation rates for the photo-generated carriers in the core/shell structure. © 2013 Elsevier B.V.

In this work we report on the self-assembly of five non-phospholipid polyglycidol conjugates in aqueous solution. The polymers are composed of a linear polyglycidol chain (degrees of polymerization, DP, are in the 8–110 range) linked to a strongly hydrophobic lipid-mimetic residue. Their behavior in dilute aqueous solution is investigated by a combination of experimental techniques – UV-vis spectroscopy, static and dynamic light scattering, fluorescence measurements, conventional and cryogenic transmission electron microscopy, and small angle X-ray scattering. The polymers spontaneously self-associate above a certain critical concentration, which depends on polyglycidol DP and temperature. According to the thermodynamic data, the self-assembly is an enthalpically disfavored endothermic process, driven by positive entropy contribution. The polymers with polyglycidol DP of 23 and above form small core–corona micelles. The latter are parameterized and the experimental values are compared to those of micelles of the commercially available poly(ethylene glycol)-derivatized lipids and other related non-phospholipid poly(ethylene glycol) conjugates. The polymer of the lowest polyglycidol DP form lamellar structures of co-existing morphology – spherical vesicles and highly anisotropic, elongated bilayer flakes.

This paper studies the material response of UNS S31603 to incremental particle impact and evolution of surface and subsurface wear with time during erosion–corrosion. Multiple tests were performed at increasing time duration from 0.5 min to 2 h using a slurry pot erosion tester with 3.5% NaCl and 1 wt.% silica sand at a test velocity of 7 m s−1. SEM, FIB and TEM were used to investigate the mechanisms and microstructural changes that arise during this process. Between 0.5 min and 20 min of testing, when the particles are impacting the fresh uneroded surface, material removal occurs through the formation of prominent lips and deep craters. After a duration of 20 min, when the surface has been completely covered with a layer of lips and craters, a second layer starts forming. Between 0.5 min and 20 min the depth of the nanocrystalline region formed subsurface increases with direct particle impact on the surface. As the top surface layer becomes work hardened, load is transmitted by particle impact to the bulk grains leading to the formation of nano and micro sized grains. TEM investigation on the single particle impact crater revealed that deformed nanograins and twinning are formed immediately beneath the impact crater. TEM analysis of the specimen exposed to erosion–corrosion for 5 min also revealed the formation of deformed nanograins and twinning due to the high strain rates. It is believed that the compact fine grained microstructure makes it difficult for anodic dissolution to occur. However, the depassivation of the oxide film and the formation of micro galvanic cells on the deformed metal will enhance corrosion. A graph of mass loss rate versus time plotted gives good correlation with surface and subsurface features observed. Physical models are developed based on these observations.

It is well established that nanosized surface topography significantly affects cell response at a biomaterial surface. Here we used a through-mask anodization technique to fabricate well-defined titania nanopillars with tunable feature sizes from 15 to 100 nm on bulk titanium (Ti) substrates and studied their effects on initial attachment and spreading of osteoblast-like cells (MG63). An increase of titania pillar height from 15 to 100 nm resulted in reduced spreading of MG63 osteoblast-like cells and the higher pillar structures also gave rise to heavily elongated cells. By using a FIB/SEM dual beam microscope the interface between MG63 cells and nanopatterned Ti surfaces could be studied in more detail. It was found that the higher pillar structures prevented the cells to conform to the surface topography leaving voids in between the cells and the substrates. The results found in this study agree with previous studies that cells response better to surfaces with smaller (

This paper presents a cost effective route for serial fabrication of 3D structures and the achievement of function and length scale integration (FLSI) in products. A complex 3D functional pattern was designed and then used to validate this route for serial manufacture of component that integrates micro and nano scale functional features. It employs a viable master-making process chain that integrates, innovatively compatible and at the same time complementary, structuring and replication technologies to fabricate Ni shims. The shims are then utilised for the hot embossing of structures incorporating different 2.5D and 3D length-scale features. The resulting 3D profiles at different stages of the process chain were investigated and the factors affecting its overall performance were analysed.

This paper reports on the adaptation of standard complementary metal oxide semiconductor (CMOS) integrated circuit (IC) technology for biocompatibility, enabling a low-cost solution for drug discovery pharmacology, neural interface systems, cell-based biosensors and electrophysiology. The basis for the process is the anodisation of IC aluminium electrodes to form nanoporous alumina. The porous alumina was electrochemically thinned to reduce the alumina electrode impedance. For applications where a porous electrode surface is either preferred or acceptable, we demonstrated that porosity can be manipulated at room temperature by modifying the anodising electrolyte to include up to 40% polyethylene glycol and reducing the phosphoric acid concentration from 4% (w/v) to 1%. For applications requiring a planar microelectrode surface, a noble metal was electrodeposited into the pores of the alumina film. Limited success was achieved with a pH 7 platinum and pH 5 gold cyanide bath but good results were demonstrated with a pH 0.5 gold chloride bath which produced planar biocompatible electrodes. A further reduction in impedance was produced by deposition of platinum-black, which may be a necessary additional step for demanding applications such as neuronal recording. During this work a capability for real-time electrochemical impedance spectroscopy (EIS) was developed to study anodisation, barrier oxide thinning, oxide breakdown and electrodeposition processes. To study the pore morphology, focused ion beam (FIB) was employed to produce cross-sectional cuts of the IC features which were inspected by SEM with an ‘In-lens’ detector. The anodisation process and the optional electrodeposition steps require only simple bench equipment operated at room temperature and is therefore a viable route for manufacturing low-cost biocompatible electrodes from standard CMOS ICs.

We fabricated films of Au onto single crystal alumina (Al(2)O(3)(0001)) and nanostructured the surface using a high resolution focused ion beam (FIB) to remove specific regions of the film. The nanostructures consist of lines and orthogonal lines cut into the film, resulting in one- and two-dimensional islands of gold. When these films are heated above 300 °C, small nanoparticles of gold form due to the dewetting of the Au film from the alumina surface. The dimensions of these islands are dictated by the nature of the nanopatterning. The isolated islands generally have the smallest nanoparticles after heating, while the unpatterned film has much larger particles. Sintering is reduced within the nanostructured metal domains due to isolation of Au islands from each other. The evaporation rate is higher within these islands, due to the smaller size of nanoparticles and hence the higher effective vapor pressure over the surface (the Kelvin effect).

This paper presents a novel process chain for fabrication of replication masters for serial manufacture. The proposed process chain is validated for serial fabrication of (large area) organic electronic devices on flexible substrates. The advantages and limitations of the component technologies in the proposed manufacturing route are discussed and their interdependencies in a process chain for producing both 2.5D and 3D nano- and micro-structures are analysed. The proposed master-making route relies on using different technologies for micro-structuring and sub-micron and nano patterning that are applied to the fabrication of Ni shims incorporating different length scale features. In particular, the capabilities of photolithography as a micro-structuring technology were combined with those of FIB machining to add sub-micron and nano-features on micro patterned fused silica templates. Then, by applying UV nanoimprint lithography such templates were validated and their nano and micro-structures were consistently replicated in one step. Finally, the feature transfer of such imprints onto Ni shims was also successfully accomplished with only minor deviations from the target dimensions.

Purification of a 4N grade Cu rod by argon plasma-arc zone melting (APZM) was carried out. Detailed impurity analysis of the Cu rod was performed using glow discharge mass spectrometry (GDMS). Three impurity behavior groups based on segregation and evaporation during APZM were discussed using the GDMS analysis. Although the impurities with segregation coefficient kℴ 1 had no significant reduction in their impurity concentrations. Some impurities, like Mg, S, Cd and Zn, were reduced much faster than the others in Cu. This was ascribed to the removal by zone refining coupled with the evaporation of impurities for Pimp/PCu > 102.

For micro replication, the base of a die should be ductile and the surface layer that will undergo processing should have a good machining response to various tool-making processes. At the same time, the resulting working surfaces of the tooling cavities should be hard; having low roughness, low wettability and high erosion resistance. To achieve such diverse properties, nano-crystalline CrC coatings deposited onto 12% Cr tool steel were investigated in this research. To verify the properties of such coatings various metallographic techniques were applied. In particular, the corrosion resistance was studied by means of potentiodynamic anodic polarisation. A scanning transmission electron microscopy analysis of the structure was performed on samples prepared with focused ion beam (FIB) machining. The mechanical properties and grain size distribution were determined and statistically analysed. In addition, X-ray diffraction, scanning electron microscopy and atomic force microscopy were used in studying the surface properties of these coatings. To investigate the response of the CrC coatings to micro- and nano-structuring technologies with high specific energy, a series of rectangular trenches were produced by FIB milling. The effects of the ion beam current, exposure time and ion fluence on the sputtering yield and roughness of the produced micro-structures were especially investigated. Some essential parameter windows for performing FIB milling with relatively high sputtering rates, higher than 1 µm/min, and at the same time achieving the best possible surface integrity were determined during the experiments.

A cost effective methodology for pattering of Nano Imprint Lithography (NIL) templates incorporating different length scale features is proposed. The approach relies on selecting the optimum processing window of different technologies for cost effective micro- and nano-patterning. Very promising results were obtained when first fused silica templates were structured by F2 laser ablation at 157nm. It was demonstrated that nano-scale features and complex 3D micro-scale features could be machined with a Focused Ion Beam (FIB) over the existing topography produced by laser ablation. Thus, a large area (up to several square centimeters) of the NIL templates is easily patterned with micro- and even meso-scale features by laser ablation while nano- and micro-scale features could be introduced locally by FIB machining. Through S-FIL process such templates were validated and the nano- and micro-structures were accurately replicated in one imprinting step.

The machining response of amorphous and polycrystalline Ni-based alloys (Ni 78 B 14 Si 8 ) when subjected to micro-second and pico-second laser processing is investigated in this research. The shape and topography of craters created with single pulses as a function of laser energy together with holes drilled in both materials were studied. Focused ion beam (FIB) imaging was used to analyse the single craters and the through holes in the amorphous and polycrystalline samples. The material microstructure analysis revealed that processing both materials with micro-second and pico-second lasers does not lead to crystallisation and the short-range atomic ordering of metallic glasses can be retained. When processing the amorphous sample the material laser interactions resulted in a significant ejection of molten material from the bulk that was then followed by its partial re-deposition around the craters. Additionally, there were no signs of crack formation that indicate a higher surface integrity after laser machining. A conclusion is made that laser processing both with short- and long-pulses is a promising technique for micromachining metallic glasses because it does not lead to material crystallisation.

Purification of 4N (99.99%) and 6N (99.9999%) purity Cu rods by hydrogen plasma-arc zone melting was carried out. Weight loss in the 4N and 6N Cu rods as a function of number of zone refined passes revealed a higher rate of impurity removal by vaporization in 4N Cu when compared to 6N Cu. Purification effect was studied by analyzing major impurities like Mg, Si, Ca, Ti, Cr, Ni and Fe by O 2 + ions and C, O, As, Cl, P and S by Cs + ion sources using secondary ion mass spectrometry. A remarkable decrease of Si, Ti and Fe impurity concentrations in Cu at x / L = 0.03 after 10 zone passes was observed, but no similar purification effect along the remaining length of the zone refined copper rod was observed. Mg, Se and Ca in the Cu rods were reduced faster by a high evaporation effect due to P i / P Cu > 10 2 . On the other hand, removal of O, C, S and Se was expectedly dominated by vaporization in the form of H 2 O, CH 4, H 2 S, and H 2 Se through thermodynamically favored reactions. The overall segregation rate of the individual impurity elements was decreased with an increase in the purity from 4N to 6N of Cu rods. SIMS analysis of trace impurities was successfully carried out on HPZM Cu for quantitative estimation.

Removal of non-metallic impurities like O, N, C and S in 4N Cu rods by argon plasma-arc zone melting and hydrogen plasma-arc zone melting was investigated. The experimental results were discussed on the basis of thermodynamic estimation. Substantial removal of these impurities along the length of the Cu rods by argon plasma-arc zone melting was observed and relatively better removal by hydrogen plasma-arc zone melting was found to be due to activated hydrogen atoms. The removal of O, N, C and S was ascribed to the segregation effect as well as evaporation in the form of CH4 ,H 2O and H2S. As a result, it was found that hydrogen plasma-arc zone melting is a better technique to eliminate non-metallic impurities like O, N, C and S in Cu. [doi:10.2320/matertrans.MRA2008205]

The realization of complex three-dimensional structures at micro- and nanometre scale in various materials is of great importance for a number of micromechanical, microoptical, and microelectronic applications. Focused ion beam (FIB) patterning is one of the promising technologies for producing such three-dimensional structures utilizing layer-by-layer fabrication methods. A novel and efficient data preparation approach is proposed in this paper for layer-based FIB processing. By applying it, complex surfaces can be designed easily in any three-dimensional computer-aided design (CAD) package and then converted into GDSII streams for FIB sputtering or deposition. To validate the proposed CAD/CAM approach an experimental study was conducted. The factors that can affect the accuracy of the structures produced by layer-based FIB processing are also discussed. By assessing all stages of the proposed approach and the results of its experimental validation, conclusions are drawn about its applicability.

The selective oxidation of methane to methanol has been studied using trimetallic AuPdCu/TiO2 catalysts prepared by incipient wetness impregnation. They are able to catalyse the selective oxidation of methane to methanol under mild aqueous reaction conditions using H2O2 as the oxidant. When compared with bimetallic, Au-Pd/TiO2 analogues, the new trimetallic catalysts present productivities which are up to 5 times greater under the same test conditions, and this is coupled with methanol selectivity of up to 83 %. Characterisation shows that whilst Au-Pd is present as Au- core Pd- shell nanoparticles, copper is present as either Cu or Cu2O in < 5 nm particles.

A dual beam scanning electron microscopy (SEM)/focused-ion-beam (FIB) system was used to pattern fused silica coated with a thin Cr layer. Features were characterised by atomic force microscopy (AFM) and SEM. The milled depth, surface roughness and the evolution of feature profiles as a function of ion fluence were investigated. It was found that the milled depth in fused silica substrates was linearly dependent on the ion fluence within the studied range. Features topography measurement revealed that after removing completely the Cr layer, an increase of the ion fluence resulted in a slight rise of surface roughness, however, the maximum root mean square (RMS) values were still less than 2.5nm. More importantly, compared with the roughness of an unprocessed area on the substrate, an improvement of the surface finish of about 300% was obtained. The results demonstrated that FIB technology could be an alternative solution for producing nano-imprinting templates.

The machining response of amorphous and crystalline Ni 78 B 14 Si 8 was investigated when structuring substrates using focused-ion-beam (FIB) milling. In particular, the sputtering yield as a function of the scan speed, and the effects of ion fluence and scan speed on the milled depth were studied. The ion fluence dependent evolution of the cross-sectional profiles of trenches was examined by atomic force microscopy (AFM). When milling amorphous Ni 78 B 14 Si 8 , it was found that the sputtering yield first decreased with increasing the beam scan speed, then kept constant within the scan speed range, up to 710 nm/s, investigated in this work; it was also found that the milled depth was almost proportional to the ion beam fluence. The patterning of polycrystalline Ni 78 B 14 Si 8 resulted in anisotropic milling-rates due to the varying orientation of the grains in the material. The analysis of the profile evolution in both materials indicated that the surface finish of trenches was scan speed, ion beam fluence and scan strategy dependent. The study demonstrated that direct patterning by FIB could be used for producing masters in amorphous Ni-based alloys for injection moulding and hot embossing.

A dual-beam scanning electron microscopy (SEM)/focused-ion-beam (FIB) system was used to pattern fused silica substrates coated with a 15 nm thin Cr layer. The dimensions of fabricated features together with their surface morphology and profiles were investigated by SEM and atomic force microscopy (AFM). The study demonstrated that with the increase of the ion beam fluence the sputtering rate of the fused silica decreased non-linearly. Also, it was found that initially the sputtering rate increased with the increase of the beam current, after reaching a maximum value, it started decreasing when further beam current increment was performed. Compared with unprocessed areas, the surface finish of the features fabricated by FIB exhibited a significant improvement, and the ion fluence influence on the surface roughness of trenches with low aspect ratios could be considered as negligible. Using a fine beam probe, nano-gratings in the form of grooves with a width down to 54 nm and an aspect ratio higher than three were fabricated. The study showed that FIB machining could be an alternative technology to e-beam lithography for producing fused silica templates for UV nanoimprinting.

This study showed that substrate rotation plays an important role in the growth of high-quality β -FeSi 2 epitaxial film on hydrogen terminated Si (1 1 1) substrate using molecular beam epitaxy (MBE). The present work elucidated the substrate rotation effects on morphology, thickness, and purity. Results verified that substrate rotation is essential to grow thicker epilayers with better morphology and compositional uniformity. In addition, purity analyses indicated that substrate rotation increases the concentration of non-metallic impurities (H, C, and O), but does not further introduce metallic impurities into β -FeSi 2 films.

High quality Cd 1− x Zn x Te, x = 0.04 epilayers are successfully grown directly on hydrogen-terminated Si(111) substrates by hot wall epitaxy method. Growth conditions are optimized in order to grow single crystal films with desired composition. It is found that surface morphology of the epilayers is dramatically affected by the growth temperature and the growth rate at the early stage of the crystal growth. Applying limited high substrate temperature of T sub = 440 °C and low growth rate of 0.04 μm/h, the crystallinity is significantly improved and for the first time a pseudomorphic 2D growth is observed notwithstanding of the large lattice mismatch. Designing a suitable two-step growth process makes it possible that Cd 1− x Zn x Te/Si(111), x = 0.04 epilayers are fabricated with good surface morphology, which could be used as lattice matched substrates for MCT and MCZT epitaxy.

This work describes a successful post fabrication method of applying a plasmonic grating to the surface of a mounted AlGaInP LED device. A Carl Zeiss 1540 XB Focused Ion beam system was used to mill holes in a thin gold layer with a periodicity of around 540 nm. Measurements of the total light output of the device compared with a standard un-textured device show that the plasmonic grating was found to significantly affect the light output characteristics such that the overall light output was reduced. This is attributed to the fact that only p-polarised light can interact with the hole array. Furthermore, the onset of saturation in the textured device was not evident as compared with the un-textured device. This is attributed to improved current spreading in the device due to the top gold layer. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A formulation including dissolved phosphorescent iridium complex has been synthesised as a resist for step and flash imprint lithography (S-FIL(TM)). Functional properties of the resist after curing are demonstrated and structures as small as 50nm have been successfully imprinted with this material onto a 4in. silicon wafer. Fluorescent microscopy images demonstrate increased fluorescent signals where arrays of nano structures are imprinted. This technique of direct imprinting of functional materials could potentially lead to rapid, high throughput and low-cost fabrication of nanoscale organic devices and circuits.

To study the toxicity of nanoparticles under relevant conditions, it is important to reproducibly disperse nanoparticles in biological media in in vitro and in vivo studies. Here, single-walled nanotubes (SWNTs) and double-walled nanotubes (DWNTs) were physicochemically and biologically characterized when dispersed in phosphate-buffered saline (PBS) and bovine serum albumin (BSA). BSA-SWNT/DWNT interaction resulted in a reduction of aggregation and an increase in particle stabilization. Based on the protein sequence coverage and protein binding results, DWNTs exhibited higher protein binding than SWNTs. SWNT and DWNT suspensions in the presence of BSA increased interleukin-6 (IL-6) levels and reduced tumor necrosis factor-alpha (TNF-α) levels in A549 cells as compared to corresponding samples in the absence of BSA. We next determined the effects of SWNTs and DWNTs on pulmonary protein modification using bronchoalveolar lavage fluid (BALF) as a surrogate collected form BALB/c mice. The BALF proteins bound to SWNTs (13 proteins) and DWNTs (11 proteins), suggesting that these proteins were associated with blood coagulation pathways. Lastly, we demonstrated the importance of physicochemical and biological alterations of SWNTs and DWNTs when dispersed in biological media, since protein binding may result in the misinterpretation of in vitro results and the activation of protein-regulated biological responses.

We report the behavior of Au nanoparticles anchored onto a Si(111) substrate and the evolution of the combined structure with annealing and oxidation. Au nanoparticles, formed by annealing a Au film, appear to “float” upon a growing layer of SiO2 during oxidation at high temperature, yet they also tend to become partially encapsulated by the growing silica layers. It is proposed that this occurs largely because of the differential growth rates of the silica layer on the silicon substrate between the particles and below the particles due to limited access of oxygen to the latter. This in turn is due to a combination of blockage of oxygen adsorption by the Au and limited oxygen diffusion under the gold. We think that such behavior is likely to be seen for other metal–semiconductor systems.

In order to broaden the application domain of microsystems-based products, a number of processing chains that are complementary to those used for batch-manufacturing of micro electro mechanical systems (MEMS) have been recently proposed by the research community. Such alternative process chains combine micro and nano structuring technologies for master making with replication techniques for high throughput such as injection moulding (IM). In this research, two new process chains were investigated for replicating structured surfaces that are inspired by nature. In particular, a study was conducted to replicate structures incorporating functional features found on the eye of a household fly and on a shark skin. Such features were initially designed by applying a bio-mimetic modelling approach to generate the 3D models necessary to achieve the targeted surface functionality and thus to investigate the feasibility of “embedding” them in existing and new emerging products. The proposed two process chains employ micro-second (ms) and pico-second (ps) laser ablation and focused ion beam (FIB) milling to perform micro and nano structuring, respectively. The feasibility of applying them for producing masters for replicating bio-inspired surface structures was investigated by performing micro injection moulding trials. The results showed that such micro and nano structured surfaces can be replicated successfully, and the two process chains can be considered as promising manufacturing routes for serial production of parts incorporating bio-inspired surface structures.

The machining response of metallurgically and mechanically modified materials when processed by employing the microwire electrical discharge machining (μWEDM) technology is reported in this paper. In particular, the effects of the material microstructure on resulting surface integrity of Al5000 series aluminium alloys after μWEDM processing is studied. The machining response of an ‘as received’ aluminium alloy was compared against the results obtained on samples processed through extrusion strain hardening and severe plastic deformation. Especially, the process–material effects on the resulting microhardness, phase content changes, heat-affected zone, surface roughness, microcracks, recast layer, material removal rate, and element spectrum after both rough and finishing μWEDM cuts were investigated. This study shows that an ultrafine grained (UFG) Al5083 exhibits not only superior mechanical properties but also the machining response to μWEDM is favourable. A reduction of the recast layer after μWEDM was observed when compared with ‘as received’ and ‘conventionally’ processed Al5083.

A novel process chain for master tool fabrication for the replication of micro and nano features is presented in this paper. The proposed process flow relies on using complementary direct write and replication technologies for micro- and nano-structuring over relatively large areas. Results are presented when the process chain is implemented for the production of 5”x5” Ni shims of 2.5D topography of different test structures incorporating different feature sizes.

We report results relating to the thermal stability of nanoparticles and show a remarkable effect of nanostructuring of the metal. Au films are nanostructured by focused ion beam sputtering (FIB) to produce isolated areas of metal, which are imaged by atomic force microscopy (AFM). Images of the surface show that, if the islands are made small enough, the metal in the islands is lost by evaporation, whereas the nonfabricated areas outside are relatively stable and the nanoparticles remain present there.

Metallic glasses have been preferred to crystalline alloys for applications in microelectronics mechanical systems and die components because of their ease of formability and excellent mechanical properties. This paper presents the machining response of amorphous and polycrystalline Ni-based alloys (Ni78 B14 Si8) and Fe alloys (Fe81 B13.5 Si3.5 C2) when subjected to micro-second and pico-second laser processing. The shape and topography of craters created with single pulses as a function of laser energy together with holes drilled and laser milled areas in both materials were studied. Focused ion beam (FIB) imaging and Energy Diffraction Spectroscopy (EDS) were used to analyse the single craters, through holes and milled trenches in the amorphous and polycrystalline samples. The material microstructure analysis revealed that processing both materials with micro-second and pico-second lasers does not lead to crystallisation and the short-range atomic ordering of metallic glasses can be retained. When processing the amorphous sample the material laser interactions resulted in a significant ejection of molten material from the bulk that was then followed by its partial re-deposition around the craters. Additionally, there were no signs of crack formation that indicate a higher surface integrity after laser machining. This integrity is closely related to the nature of the metallic glass. A conclusion is made that laser processing both with short- and long-pulses is a promising technique for micromachining metallic glasses because it does not lead to material crystallisation, preserving the good mechanical properties of these sort of materials.

The paper demonstrates that the ion beam milling process can be modelled as a local isotropic etching without taking into account the material re-deposition during the sputtering. It also presents a software, IonRevSim, specifically developed to simulate the 3D ion structuring and thus to validate the milling process and if necessary to optimise off-line its processing parameters. In particular, employing the IonRevSim software it is possible to prepare the necessary data for performing 3D ion milling and then to simulate the 3D structuring process with the aim to minimise the deviation of resulting machined surface from the targeted one. These two main functions of the software and their respective operating modes are discussed in the paper. An experimental verification based on an optimised data generated by IonRevSim was performed using both FIB and multi-beam CHARPAN PMLP tools. For both ion-patterning techniques a good agreement between experimental and simulation results was demonstrated when applied for producing relatively low aspect ratio structures.

This paper describes a new data preparation technique, which allows for the design of optical lenses in a conventional CAD package and immediate transfer to a lithographic system, for example Electron Beam or Focused Ion Beam Lithography. Most importantly, we show that this approach could be used to fabricate lens arrays in templates for Step-and Flash Imprint lithography onto 4iquestwafers. One application for this is to enhancing AlGaInP LED performance by texturing the top current spreading layer.