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In this paper we present the design and implemen tation of a small-scale marine sensor network. The network monitors the temperature in the Baltic Sea on different heights from the water surface down to the bottom. Unlike many other wireless sensor networks, this network contains both a wired and a wireless part. One of the major challenges is that the network is hard to access after its deployment and hence both hard- and software must be robust and reliable. We also present the design of an advanced buoy system featuring a diving unit that achieves a better vertical resolution and discuss remaining challenges of sensor networking in aquatic environments.

We present for microfluidics the strongest yet mechanical micropump in sub-cm3 size, using simple processes and materials such as Parylene coated stainless steel stencils, paraffin, and copper clad polyimide. The pump consists of two active valves and one pumping chamber, each operated by a paraffin actuator. Each actuator is driven by a square pulse waveform with an amplitude of 1.8 V. The pump sequence has a period time of 14.4 s, resulting in the pumping of water up to 50 bar (5 MPa) back pressure without leakage and a flow rate of 0.75 muL/min.

We present the design, fabrication and characterization of vertical thermopile infra-red (IR) sensors. The sensors are produced in batches in a standard flexible printed circuit board (flex PCB) material. The vertical design opens up for large area detection and longer thermopile chains. The sensors consist of series of 88 vertically interconnected thermocouples in a 75 mum thick polyimide foil (Kapton HNtrade). The sensors showed a voltage response to an IR pulse of 1.2 V/(W/mm2).

This paper presents a low-profile inverted-F antenna for 3D integrated wireless sensor applications at the 2.4 GHz "industrial, scientific, medical" band (ISM). The proposed antenna with an equivalent model of the 3D integrated wireless sensor was simulated assuming in free-space conditions and fabricated on a piece of thick commercial FR-4 epoxy laminate combined with a stair configuration metal block. Both the impedance and radiation performance of the proposed antenna integrated in the wireless sensor cube were experimentally measured and then optimized. The measurements show that about 60 MHz -10 dB return loss bandwidth and -8.3 dBi gain are achieved at 2.4 GHz. Although the proposed antenna has low radiation efficiency due to the limited available space and the lossy epoxy based FR-4 substrate, it features a low-profile and cost effective solution for the particular applications.

Gain and efficiency enhanced flip-up antennas for 3D integrated wireless sensor applications

Swift heavy ion beam-based lithography using masks of self-assembled materials has been applied for transferring well-ordered micro- and nanopatterns to rutile TiO2 single crystals. As the induced damage has a high etching selectivity the patterns can be developed in HF with very high contrast. Here we present resulting patterns when using a mask of self-ordered silica spheres. Since the obtained structures are replicas of the mass distribution of the applied mask, the shape and size of resulting structures depend on the geometric configuration of the silica sphere layers. In addition, the resulting pattern can be tuned by varying the applied ion energy and fluence. Direct modifications of the optical properties of TiO2 in a well-defined pattern are also presented.

A production scalable technique is presented to make hemispherical coil antennas by using a stretchable printed silver paste conductor and plastic thermoforming. To ease the fabrication process an ...

Nanowires (NWs) and nanoparticles (NPs) of different materials have been grown using either a polycarbonate porous membrane or mesoporous silica as template. The NWs have lengths between 1 and 20 microns; their diameter, as well as the dimensions of the NPs, are in the range of a few hundreds of nanometers. In order to test their electrical characteristics, some of these NWs and NPs have been electrically contacted by using submicrometer sized metallic Pt stripes deposited using an electron and/or ion beam in a focused ion beam (FIB) system. The preliminary results show that the method used is well suited for fabrication of contacts to NWs and NPs, whose electrical behaviour can be easily evaluated. These nanocontacts could help to design future nanodevices.

We present the potentially strongest micropump in sub-cm/sup 3/ size yet for microfluidics, using simple processes and materials such as epoxy, paraffin, and polyimide. Utilizing the large volume expansion associated with the melting of paraffin for actuation, a pump consisting of two active valves and one pumping chamber operated by three identical paraffin actuators has been realized. UV-curable epoxy, which encloses the paraffin, forms the channel structure and joins the glass cover, actuator membrane and resistive heaters for melting the paraffin, is the main construction material. With water as a pumping fluid and a 2 V drive voltage, the valves were subjected to pressures up to about 1 MPa without showing any leakage. A flow rate of 74 nl/min was obtained in normal operation.

High aspect ratio microstructures are today of utterly importance in MEMS. The process described in this paper can be used to produce deep, vertical microstructures in polyimide based materials, used in e.g. flexible printed circuit boards (FPCBs). Stacked polyimide and metal layers have the potential of integrating microelectronic circuits with above applications. The process is capable of producing regions with perpendicular sub-micron metal wire connections at numerous, arbitrarily specified locations. The flexible laminate is irradiated with heavy ions creating a vertical damage anisotropy (ion tracks) in the polymer layer. Lithographically defined apertures in the metallic layer define the geometry. The tracks exposed are selectively developed forming nanometer-wide pores. Metallic structures have been replicated in these pores by electrodeposition of metals. Demonstrator microstructures and highly vertical, through hole microvias have been fabricated. Ion track technology is promising for ultra-high density via batch production and has a potential of further miniaturizing via dimensions.

We have demonstrated the ability to combine microsystem technologies with sub-micron wire fabrication in polyimide based flexible printed circuitry board (PCB) laminates. Clusters of sub-micron wires in each via enables that no increase of resistance is shown for copper wires up to 30 GHz. A toroidal inductor is fabricated as an example of the application of ultra-high density via interconnects.

The authors present experimental evidence for thickness‐field excitation of thickness‐shear vibrations in GaAs as an example material for zincblende‐crystal semiconductors. The resonance frequency is shown to agree perfectly with theory. This gives an alternative to the composite resonators in miniaturized local oscillators for, e.g., monolithic microwave integrated circuit applications.

A method to achieve deep and direction independent structuring of laterally arbitrary geometry in single crystalline quartz is demonstrated. It is based on local etching of the latent track induced anisotropy resulting from heavy ion bombardment, and is independent of crystallographic orientation. Previous results are briefly reviewed and a more systematic and thorough study is presented together with the first results from a new modified technique based on shadow masking. Miniature tuning fork structures have been realised, and the suitability for frequency control is discussed on experimental basis.

Micromachining by ion track etching (MITE) offers a new way to impose an arbitrary etch anisotropy on amorphous and crystalline dielectrics and is demonstrated in single crystalline quartz. The technique can be used to obtain very deep structures with extreme aspect ratios and line widths. At present, depths down to several hundred micrometers with aspect ratios larger than 100 can be obtained. The MITE process has been explored using single crystalline quartz of the AT-cut and Z-cut orientations, using fast heavy ions /sup 197/Au and /sup 129/Xe (11.6 MeV/u and 11.4 MeV/u, respectively). Complex, three-dimensional quartz structures of 80 /spl mu/m height with vertical or inclined walls were produced. The and limitations of the process are discussed.

Two separate schemes for bulk micromachining are presented together with experimental results on microfabricated cantilever beam structures indicating that conventional lithography and wet etching techniques can be used to produce geometrically well-defined, high-strength GaAs elements (fracture limits >

Diamond is difficult to micromachine due to its hardness and chemical inertness. Therefore it is preferable to make use of diamond replication. The well developed area of silicon micromachining makes it possible to fabricate complicated structures that can be used as moulds for diamond. A microstructure technology for diamond replicas following the authors process flow scheme below is given. Different silicon microstructures have been manufactured by standard bulk micromachining processes i.e. lithography, wet etching, and dry etching, to evaluate diamond replication.

The key performances of optical filters requested by optical communications for wavelength-division multiplexing (WDM) systems are: (i) a high wavelength selectivity, enabling the selection of neighboring channels 1.6 nm apart with a crosstalk ratio of 20 dB, (ii) a continuous wavelength tuning range of about 30 nm around 1.55 /spl mu/m, with no degradation of the selectivity. We demonstrate the design and the fabrication of a vertical micromachined InP-air gap based Fabry-Perot filter, continuously tunable via electrostatic micromechanical actuation of the cavity air gap, which meets the WDM system requirements.

Deep and vertical microstructuring by wet etching of swift heavy ion induced damages (ion tracks) is here performed in materials possessing a less attractive anisotropy or lacking crystallinity, such as single crystalline quartz, mica, glass and polycarbonate. The concept is named micromachining by ion track etching, MITE. Quartz resonator structures are made by uniform irradiation with ions and etching in lithographically defined areas. The latent, i.e., unetched, damage in the remaining structure is shown to be of little significance for the Q-value and thermal behaviour of such resonators. A new scheme, projection MITE, resting on direct patterning by a shaped ion beam to eliminate also this influence is demonstrated. The definition of edges and corners vs. the ion fluence is investigated. The projection MITE allows miniature structures to be etched out of substrates without the need of a deposited and patterned masking material, which is also shown. Furthermore, a first attempt to demonstrate negative and density-projection techniques based on this kind of MITE is made.

Indium phosphide based micro opto electro mechanics (MOEMs) hold promises of micromechanical applications in the longer wavelength region, and in particular for applications in telecommunication networks. Recent work on indium phosphide micromechanics is presented: the mechanics, the micromachining and fabrication, and possible future devices and applications.

A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements has been manufactured and evaluated. The combustor was made of High-Temperature Co-fired Ceramic (HTCC) alumina green tapes. The device has a built-in screen printed heater and a temperature sensor made of platinum, co-sintered with the ceramic. A copper oxide oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide reduction processes. The temperature sensor was calibrated by use of a thermocouple. It demonstrates a temperature coefficient resistance of 4.66×10−3/°C between 32 and 660 °C. The heat characterization was done up to 1000 °C by using IR thermography, and the results were compared with the data from the temperature sensor. Combustion of starch confirmed the feasibility of using copper oxide as the source of oxygen of combustion.

We have demonstrated the ability to combine microsystem technologies with nanowire fabrication for magnetic field sensor applications. The substrate material used is a thick polyimide foil, the very same material flexible printed circuit boards are composed of. Thus, compatible and appropriate for microelectronic integration.

Microoptoelectromechanical (MOEMS) systems with InP based micromechanics are proposed for devices with wide tuning ranges in the optical wavelengths where InP optoelectronics are normally used. To evaluate if these InP based micromechanical structures may be strong enough the mechanical strengths of surface micromachined epitaxial InP micro beams are evaluated. Reactive ion etching (RIE) with CH4:H2:H2Ar is used to structure the beams. A sacrificial InGaAs layer is below the InP microstructures and selectively etched by HCl:H2O2:H2O in ratios 1:1:10 to release the InP beams. Sublimation of tert-butanol is used to dry the micro structures. The RIE conditions are shown to be of large importance, since the induced surface defects are here the dominant reasons for fracture. Bending strength values up to 3.1 GPa were measured, i.e. much higher than for the strongest construction steel. Weibull statistics show that it is possible to make micromachines for typical MOEMS applications with acceptable loss in yield due to fracture probability, i.e. with a fracture probability of 0.0001 for 100 MPa maximum bending stress.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Viton is an elastomer with low permeability and high chemical resistance. This paper presents the main characteristics and technical issues involved in fabricating Viton-based microfluidics by micromoulding, bonding and metallization. A PDMS (polydimethylsiloxane) mould is used to imprint the Viton compound in a curing step that is followed by a post-curing without the mould. Viton was fusion bonded, with high quality, to itself and to stainless steel when clamped together during a post-curing step. Having low permeability to hydrocarbon liquids, Viton is a well-suited elastomer for making paraffin membrane microactuators, as demonstrated here. These kinds of microactuators may find their applications in fluid handling with hydraulic oils, in vacuum systems or in reactors and analytical systems, where Viton comes in direct contact with fluids that would permeate or degrade other elastomers.

The authors demonstrate a complete surface micromachining procedure including a several steps of epitaxial regrowth in the fabrication of a laterally mobile GaAs structure (a wheel), as well as a sensor structure (a bridge). The enormous etch selectivity and the lack of internal stresses in the AlGaAs-GaAs system, combined with the excellent thickness control provided by MOCVD, make it possible to manufacture micromechanical structures that are similar to structures previously micromachined in the polysilicon-silica system. However, it is noted that economic factors and processing difficulties make the potential for GaAs micromechanics much more limited than for polysilicon. >

We present a 2.4 GHz unbalanced loop antenna that can be stretched along multiple dimensions simultaneously. It was realized by incorporating room temperature liquid metal alloy into microstructured channels in an elastic material. The demonstrated prototype exhibits a stretchability of up to 40% along two orthogonal orientations as well as foldability and twistability. Port impedance and radiation characteristics of the nonstretched and stretched antenna were studied numerically and experimentally. Measured results indicate a radiation efficiency of more than 80%.

We developed a new approach to separate bacteria from human blood cells based on soft inertial force induced migration with flow defined curved and focused sample flow inside a microfluidic device. This approach relies on a combination of an asymmetrical sheath flow and proper channel geometry to generate a soft inertial force on the sample fluid in the curved and focused sample flow segment to deflect larger particles away while the smaller ones are kept on or near the original flow streamline. The curved and focused sample flow and inertial effect were visualized and verified using a fluorescent dye primed in the device. First the particle behaviour was studied in detail using 9.9 and 1.0 microm particles with a polymer-based prototype. The prototype device is compact with an active size of 3 mm(2). The soft inertial effect and deflection distance were proportional to the fluid Reynolds number (Re) and particle Reynolds number (Re(p)), respectively. We successfully demonstrated separation of bacteria (Escherichia coli) from human red blood cells at high cell concentrations (above 10(8)/mL), using a sample flow rate of up to 18 microL/min. This resulted in at least a 300-fold enrichment of bacteria at a wide range of flow rates with a controlled flow spreading. The separated cells were proven to be viable. Proteins from fractions before and after cell separation were analyzed by gel electrophoresis and staining to verify the removal of red blood cell proteins from the bacterial cell fraction. This novel microfluidic process is robust, reproducible, simple to perform, and has a high throughput compared to other cell sorting systems. Microfluidic systems based on these principles could easily be manufactured for clinical laboratory and biomedical applications.

This paper presents one of the strongest mechanical sub-cm3 sized micropumps for microfluidics. It consists of two active valves and one pumping chamber, each operated by a paraffin actuator that is driven by a low-voltage square pulse waveform. The pump is fabricated in a simple process using parylene-coated stainless steel stencils, paraffin and copper clad polyimide. When driving the pump at 0.07 Hz and 2.0 V (0.8 W) per actuator, it pumped water without leakage at a flow rate of 0.75 µL min−1 up to above 50 bar (5 MPa) back-pressure. The frequency dependence was evaluated and a maximum flow rate of 1 µL min−1 at 0.21 Hz and 1.8 V was observed. A thermomechanical FEM analysis, which was in good agreement with experiments at low frequencies, predicts the behaviour at higher frequencies.

This work presents novel components for on-chip storage and dispensing inside a lab-on-a-chip (LOC) for applications in immunoassay point-of-care testing (POCT), where incubation and washing steps are essential. It involves easy-to-use on-chip solutions for the sequential thermo-hydraulic actuation of liquids. The novel concept of combining the use of a rubber plug, both as a non-return valve cap and as a liquid injection interface of a sealed reservoir, allows simple filling of a sterilized cavity, as well as the storage and dispensing of reagent and washing buffer liquids. Segmenting the flow with air spacers enables effective rinsing and the use of small volumes of on-chip stored liquids. The chip uses low-resistance resistors as heaters in the paraffin actuator, providing the low-voltage actuation that is preferred for handheld battery driven instruments.

Thermopiles are important components in infrared thermal detectors, thermoelectric generators and thermoelectric coolers. We present a thermopile structure with up to 224 vertically arranged thermocouple legs in a polyimide flex material. The thermopile is optimized for infrared thermal radiation detection and is fabricated using printed circuit board-like (PCB-like) processing. Each thermoelectric leg consists of a bundle of a few hundred sub-micrometre-sized strands of either antimony or nickel. These metal wire bundles were achieved by employing ion track technology on the polyimide foil, resulting in a porous dielectric material. Electrochemical methods were used to grow the thermoelectric materials in the pores. The plating mask was produced in a laminated dry photoresist. A small metal cross section, 20 µm2 (1 vol%), ensured a low heat exchange between the two surfaces of the flex. The typical resistance per thermocouple was 34 Ω. A responsivity to irradiance of 4.3 V mm2 W−1 was measured when heating with a white light source (irradiance 1 mW mm−2).

An empirical relationship between the long wavelength edge of the residual ray band in the IR- reflectance of partly ionic compounds and bulk hardness is demonstrated. The group of materials studiedincludes alkali halides, semi-conductors and some hard compounds, mostly with cubic structure and a few with hexagonal. The correlation is shown for the Young modulus, the melting temperature and also to some extent the indentation hardness. The Young moduli cover a range from 10 to almost 500 GPa and themelting temperatures vary from 600 to 3000°C. 2. INTRODUCTION Residual rays ( German: Restrahlen Bands), i.e. bands of high reflectance caused by lattice excitation ina crystalline solid, are characteristic for the infrared properties of alkali halides. In these relatively softciystals with purely ionic bonding, the bands occur in the wavelength region 30-200 tm, shifting towardslonger wavelengths the heavier the ions of the lattice are. This property of ionic crystals has been exploitedin infrared instruments for wavelength discrimination by multiple reflections. However, the appearance of

A fabrication process for high aspect ratio plated through-hole vias is presented for flexible printed circuit boards. A 75 ?m thick porous Kapton foil that allows direct definition of high aspect ratio through-hole vias by dry photoresist film lithography and electrodeposition is presented. Pretreatment with swift heavy ion irradiation and wet etching define the pore density and porosity of the foil, similar to ion-track-etched filter membranes. Thin film metallization of a seed layer and lithography of a laminated dry photoresist film define the via sizes and positions. Subsequent through-hole electrodeposition produces vias consisting of multiple wires, where each open pore defines one wire. The via geometries are characterized by scanning electron microscopy. The electrical properties of the vias are characterized by resistance measurements. Vias with an aspect ratio over 2 and a side length of 33 ?m show high yield with low resistance and low variation in resistance.

Ion track lithography has been applied for transferring the self-ordered nanopattern of porous anodic alumina to single-crystalline rutile TiO2 substrates. As a result, nanometre resolved arrays have been fabricated with an aspect ratio ranging from 5 to 16, over areas of several square millimetres. Differences in the expected aspect ratio of the resulting nanopores in rutile TiO2 single crystals are analysed and discussed. Some of these differences may be ascribed to varying densities of the mask material.

The authors present a method for high aspect ratio nanopatterning of high density (1010pores∕cm2) self-assembled porous alumina membrane pattern into thermally grown SiO2 on silicon. The pattern transfer is accomplished by irradiating through 2μm thick porous alumina membrane with swift heavy ions (4MeV Cl2+). Ions passing through the nanopores in the mask at a fairly high fluence (typically 1014ions∕cm2) are impinging on the substrate and creating a continuous volume of overlapping ion tracks of damage. The damage is sufficient to be selectively etched by HF vapor from an aqueous HF solution. From an alumina mask with pores of 70nm diameter, a pattern of pores of 77nm in diameter and the same distance of 100nm between the centers of the pores was transferred. The deepest observed etched pores were 355nm, giving an aspect ratio of 5, which is up to 40 times larger compare to earlier work where HF wet etching was used. This ion track lithography technique shows a potential to produce nanostructures with ev...

Self-assembled nanoporous alumina films were employed as masks for MeV ion track lithography. Films with thickness of 2 μm and pore diameters of 30 and 70 nm were attached to thermally grown SiO2 covered with a thin gold layer. The samples were aligned with respect to the beam by detecting backscattered He+ ions with the initial energy of 2 MeV. The ordered pattern of the porous alumina films was successfully transferred into SiO2 after irradiation with a 4 MeV Cl2+ beam at fluence of 1014ions∕cm2, followed by chemical etching in a 5% HF solution.

A micromachining process, using ion track etching in combination with lithographic patterning, is presented. The technique employs a substrate pre‐irradiated with swift heavy ions and uses a conventional lithographic technique to control the access of a track‐selective etching medium to the ion tracks. Experimental results show the possibility of generating high aspect ratio structures in virtually any direction in single crystalline quartz, which otherwise exhibits a strong ‘‘natural’’ anisotropy to conventional wet etching. In this way complex, three‐dimensional quartz structures of 80 μm height with vertical or pre‐defined inclination angles of the walls were produced. The process can be applied to other, even highly radiation resistant, dielectric materials such as mica and organic polymers.

The transfer of continuous-relief diffractive structures from resist into diamond by use of direct-write electron-beam lithography followed by dry etching in an inductively coupled plasma is demonstrated. The gases used for the diamond etching are O(2) and Ar. The chemical-vapor-deposited diamond substrate is of optical quality. Our results show that the transfer process generates fairly smooth etched structures. Blazed gratings with periods of 45mum and Fresnel lenses have been manufactured. The blazed gratings have been optically evaluated with a femtosecond laser operating at 400 nm. The diffraction efficiency was 68% in the first order, with a theoretical value of 100%. We intend to investigate the transfer process further and then to fabricate diffractive and refractive elements for use with Nd:YAG high-power lasers.

InP-to-Si wafer bonding has been proposed as a way of circumventing the problems associated with lattice-mismatch in heteroepitaxial growth. Therefore, in this study the dislocation density and material degradation in InP-to-Si hydrophobic bonding are evaluated. Both interface and InP bulk defects were studied using IR-transmission, atomic force microscopy (AFM) and defect-etching. When the bonded wafers were annealed below 300°C, no volume dislocations were generated in InP. However, when annealing above 300°C, the thermal mismatch stress induced large numbers of volume dislocations in InP. It was also shown that hydrophobic InP-to-Si wafer bonding unfortunately requires high-temperature annealing to achieve sufficient bonding-strength. However, a considerably lower dislocation density was observed in InP-to-Si wafer bonding than that in InP heteroepitaxial growth on Si. Also, when the samples were annealed above 400°C, asymmetric voids emerged at the interface. These voids are associated with the nucleation of indium droplets which causes microcavities at the interface where volume dislocations can sweep-out, forming surface steps. The voids completely disappeared when channel-patterned interfaces were used.

In this paper we present our in situ, oxygen plasma‐activated wafer bonding process. By keeping one wafer on the anode and the other on the cathode, we have an asymmetric plasma load on the wafers, making our bonding process interesting for low‐temperature applications where damage or defect‐sensitive active layers are bonded to less sensitive carrier wafers. As a step in optimizing the discharge parameters for plasma bonding applications, the effect of the self‐bias voltage on surface energy, oxidation rates, and damage is investigated. An optimum in surface energy was found at moderate self‐bias voltages, both at room temperature bonding and after low‐temperature annealing at 200°C. This is explained by the fact that at these voltages there is a minimum oxide thickness, which promotes the diffusion of water from the bond interface, and also by the fact that at these voltages we have the best surface cleaning conditions. Also, the surface oxide generated by the oxygen plasma seems to be reactive. With our in situ oxygen‐plasma‐activated wafer bonding process there was a major increase in surface energy for wafers bonded at moderate self‐bias volt‐ages compared to conventional wafer bonding performed in ambient air. © 2000 The Electrochemical Society. All rights reserved.

The precise crystallographic orientation of InP wafers is revealed using a crystalign pattern that is etched for a short time. A device pattern can then be aligned to the manifested direction. Alignment of V-grooves for precise cleaving of side emitting lasers is demonstrated with a precision of 0.063°

We report the fabrication of InP/air-gap Fabry-Perot resonant cavities with an improved tunability characteristic achieved through the micromachining of more flexible suspended InP beams. The micromechanical structures are electrostatically actuated. A tuning range of 55 nm is demonstrated for an actuation voltage of 12 V. The low leakage current, of less than 10 µA for a bias of up to 30 V, provides a low actuation power. The tunable air-gap cavities are fabricated by selective wet etching of InGaAs sacrificial layers. An FeCl3 based etchant is used to completely remove the InGaAs material without affecting the thickness of the InP layer. The anisotropy of the etch rate of InGaAs was also investigated and exploited in the micromachining process.

A dual-beam focused ion beam unit has been used to deposit platinum contacts on nanomaterials using both electron- and ion-assisted deposition. Characterization of deposited platinum has been performed and the feasibility of using these nanocontacts to extract electrical parameters of materials demonstrated. The advantage of combining electron- and ion-assisted deposition is discussed.

Metallic Au nanowires were electrochemically synthesized in 20 µm thick ion track etched polycarbonate membranes with the nominal pore diameter of 200 nm. Scanning and transmission electron microscopy analysis and x-ray diffraction of samples revealed that the nanowires are dense with a fcc [Formula: see text] texturing. The I-V characteristics of a single Au nanowire were investigated using a four-point microprobe set-up. The Au nanowire was placed in electrical contact with electrodes patterned on planar substrates using a dual-beam focused ion beam technique. The resistivity of the Au nanowires was found to be 2.8 × 10(-4) Ω cm.

Following the theory, ferromagnetism is predicted in Mn- doped ZnO, Indeed, ferromagnetism above room temperature was recently reported in thin films as well as in bulk samples made of this material. Here, we have prepared Mn doped ZnO by electrodeposition. The samples have been characterized by X-ray diffraction and spectroscopic methods to ensure that the dopants are substitutional. Some samples exhibit weak ferromagnetic properties at room temperature, however to be useful for spintronics this material need additional carriers provided by others means.

By combining ion track technology with ordinary low-resolution printed circuitboard lithography it is possible at low cost to create high aspect ratios via connectors, as solid plugs or consisting of bundles of sub-micron connector wires at a small total cross-section.Ion track enabled microwave circuits in flexible printed circuit boards are suggested to be used in applications like inductors, ferromagnetic resonance microwave filters, circulators and magnetoresistive sensors. In this paper we demonstrate this technology with integrated printed circuitboard devices in two different flexible polyimide-based foils (Espandex and Kapton HN), using the ultra-high-density vias and the sub-micron wires.