Continuous Wire Research Articles

Fabrication of Continuous Conducting Gold Wires by Electrospinning

An innovative approach is developed to electrospin Au polymer wires, dissolving HAuCl4 salt in ethanol followed by addition of poly(acrylic acid) with several modifications in the conventional elec...

Tuning of biased domain wall depinning fields at Permalloy nanoconstrictions

The propagation of a transverse domain wall (DW) through single asymmetric nanoconstrictions is investigated in continuous ferromagnetic planar wire structures, by localized magneto-optical Kerr effect magnetometry. Using focused ion beam (FIB) milled planar Permalloy nanowires, we propagate a DW in opposite directions through single asymmetric nanoconstriction. The DW depinning field from an asymmetric nanoconstriction strongly depends on the direction of motion of the DW relative to the trap. A depinning field bias effect is tuned by varying the constriction width from 50to200nm in 300nm wide nanowires. FIB milled nanoconstrictions, with a width as narrow as 50nm, demonstrate a bias effect. Narrowing the width of the constriction enhances the depinning field bias effect.

The Influence Of Bonding Mode and Wire Setting On The Stresses Of Metal Matrix Composite Reinforced with Continuous wire

The Influence Of Bonding Mode and Wire Setting On The Stresses Of Metal Matrix Composite Reinforced with Continuous wire

A single nanotrench in a palladium microwire for hydrogen detection

The hydrogen sensing characteristics of a single nanotrench fabricated by focused ionbeam milling (FIB) in an evaporated palladium microwire are presented. In situatomic force microscopy (AFM) measurements proved that, in the presence ofH2, the trench closes and electrically connects the initially separated parts of thewire due to the increase in volume of the material. Therewith, an electricalcurrent can be switched through the wire. With experiments under variousH2 concentrations and a mathematical model, we describe the closing mechanism of the trench withrespect to various parameters, including the substrate material, film thickness, trench size andwire dimensions. Results have been compared with those from equivalent continuous wires. ThinSiO2 and polyimide (PI) layers on silicon were used to study the effect of substrate elasticity. Sufficientlateral expansion of Pd to close trenches of up to 70 nm in width has only been observed onPI, which we attribute to its advantageous elastic properties. The scale of the responsetimes allowed the observation of two superposing effects: the chemical conversion of Pd toPdHx and the mechanical closing of the trench.

Left-handed behavior of combined and fishnet structures

The left-handed (LH) behavior of a combined structure of cut wire pair and continuous wire was experimentally studied. It was found that the LH behavior of a combined structure can still be observed as the width of cut wire pair increases until the cut wire joins the continuous wire, the so-called fishnet structure. These structures were designed, fabricated, and measured in the microwave frequency regime. In addition, we report the experimental results of the parametric study on the fishnet structure, which are also compared with the previous theoretical studies.

A planar metamaterial: Polarization independent fishnet structure

We numerically and experimentally investigate a planar metamaterial that is composed of connected cut-wire pairs and continuous wires operating at 21 GHz. The characterization was performed by using the effective medium theory. The existence of negative refraction is concluded from the transmission data of four structures: cut-wire pairs, shorted cut-wire pairs, composite metamaterial, and shorted composite metamaterial.

Preparation of Zr-Based Metallic Glass Wires for Biomaterials by Arc-Melting Type Melt-Extraction Method

New Zr-based metallic glass wires with and without bio-toxic elements of Ni and Al for the application to biomaterials were prepared by arc-melting type melt-extraction method and their characteristics were tested. The continuous metallic glass wires with a good white luster and smooth surface were obtained in various alloys such as conventional Zr-Al-Ni-Cu, Ni-free Zr-Al-Co-Cu, and Ni and Al free Zr-Ti-Co alloys. The Zr-based metallic glass wires exhibit high tensile strength reaching 1 GPa. Furthermore, the metallic glass wires showed good bending ductility and could be bent through 180 degrees without fracture. The Zr-based metallic glass wires achieve simultaneously high tensile strength, good bending ductility and high thermal stability. [doi:10.2320/matertrans.MRA2008006]

Wire Sizing and Spacing for Lithographic Printability and Timing Optimization

As the VLSI feature size has already decreased below lithographic wavelength, the printability problem, due to strong diffraction effects, poses a serious threat to the progress of VLSI technology. A circuit layout with poor printability implies that it is difficult to make the printed features on wafers follow designed shapes without distortions. The development of resolution enhancement techniques (RET) can alleviate the printability problem but cannot reverse the trend of deterioration. Moreover, over-usage of RET may dramatically increase photo-mask cost and increase the cycle time for volume production. Thus, there is a strong demand to consider the subwavelength printability problem in circuit layout designs. However, layout printability optimization should not degrade circuit timing performance. In this paper, we introduce a wire sizing and spacing method to improve wire printability with minimal adverse impact on interconnect timing performance. A new printability model is proposed to handle partially coherent illuminations. The complex printability and timing optimization problem is solved in a two-phase approach. The difficulty of the printability optimization due to its multimodal nature is handled with a sensitivity-based heuristic. A coupling aware timing driven continuous wire sizing algorithm is also provided. Lithographic simulation results show that our approach can improve the printability in term of edge placement error (EPE) by 20%-40% without violating timing, wire width, and spacing constraints.

Wire-woven bulk Kagome truss cores

A new type of periodic cellular metal called wire-woven bulk Kagome (WBK) is devised. For fabricating the WBK truss core, continuous helical wires are systematically assembled in six different directions. Through this method, the unit WBK structure, which guarantees high specific strength, is uniformly formed in the core. Therefore, with this fabrication process, which allows continuous assemblies, robust truss cores can be mass produced. Metal wires are selected for the WBK core because they can be easily hardened by heat treatments and simply handled for fabrication. For characterizing the deformation behavior of the WBK core under compression, the compressive properties, such as the effective elastic modulus and the peak stress, are predicted using force equilibrium and elastic energy conservation of the core, and obtained through experimental measurements using WBK specimens of different sizes. Moreover, the compressive performance of the WBK core is compared with those of well-known cores of different types, and the failure mechanisms are elucidated by finite element analysis about the compressive behavior of the core.

Power transmission enhancement by means of planar meta-surfaces

In this paper, the analysis and design of a planar meta-surface based on dipoles and wires is presented. The unit cell is formed by three layers, two parallel dipoles and one continuous wire. The transmission response and dispersion diagram of the unit cell are analysed step by step in order to determine the effect of each element; one dipole, two parallel dipoles and finally the two dipoles and wire unit cell. For a normally incident plane wave excitation with the E field parallel to the wires and the H field axial to the dipoles, a strong magnetic dipole moment is induced which produces a pass band around the resonant frequency and a stop band at higher frequencies. This cell is used to create meta-surfaces for antenna gain enhancement. Two configurations are analysed; the first one is a superstrate of a dipole antenna with the pass band tuned to the resonant frequency of the dipole. Due to the resonance of the superstrate inclusions, a uniform illumination is achieved, which produces high aperture efficiency and an increase of the directivity up to 6.31. By adding a meta-substrate with the stop band tuned to the resonant frequency of the dipole, an enhancement versus the conventional dipole of five times in the boresight radiation and 795 times in the front–back ratio is obtained.

The Architectural Nervous System

The Architectural Nervous System

Left-handed metamaterials: The fishnet structure and its variations

We investigate, both theoretically and experimentally, a left-handed metamaterial design composed of pairs of short slabs connected with continuous wires, operating in microwave frequency regime. The design was found to give left-handed behavior for a wide range of structure parameters, maintaining high impedance match with free space. We introduce a capacitor-inductor circuit description of the design and we show that this description can account for all the characteristics of its electromagnetic behavior, explaining also its superior performance.

Caracterização térmica e morfológica de fibras contínuas de basalto

Os basaltos são rochas vulcânicas abundantes provenientes de extensos derrames de lava. A tecnologia de fiação contínua produz filamentos de basalto na forma de fios micrométricos amorfos. Neste trabalho são apresentados resultados da caracterização térmica e morfológica de fibras longas de basalto, de diâmetro micrométrico. Estas fibras apresentaram excelente estabilidade térmica, resultando em alterações de massa menor que 1% sob aquecimento até a temperatura de 1000 ºC, em atmosfera inerte ou oxidante. Por outro lado, a ~ 800 ºC ocorreu a cristalização parcial das fibras de basalto, com a formação de fases cristalinas de silicatos e alumino-silicatos, como a anortita, da classe dos plagioclásios. A morfologia das fibras, aquecidas a 1000 ºC, foi alterada devido à fusão e cristalização das fases presentes.

Pulsed wire discharge apparatus for mass production of copper nanopowders

A pulsed wire discharge (PWD) apparatus for the mass production of nanopowders has been developed. The apparatus has a continuous wire feeder, which is operated in synchronization with a discharging circuit. The apparatus is designed for operation at a maximum repetition rate of 1.4 Hz at a stored energy of 160 J. In the present study, Cu nanopowder was synthesized using the PWD apparatus and the performance of the apparatus was examined. Cu nanopowder of 2.0 g quantity was prepared in N(2) gas at 100 kPa for 90 s. The particle size distribution of the Cu nanopowder was analyzed by transmission electron microscopy and the mean surface diameter was determined to be 65 nm. The ratio of the production mass of the powder to input energy was 362 g/kW h.

Dendritic development and plasticity of adult-born neurons in the mouse olfactory bulb

The mammalian brain maintains few developmental niches where neurogenesis persists into adulthood. One niche is located in the olfactory system where the olfactory bulb continuously receives functional interneurons. In vivo two-photon microscopy of lentivirus-labeled newborn neurons was used to directly image their development and maintenance in the olfactory bulb. Time-lapse imaging of newborn neurons over several days showed that dendritic formation is highly dynamic with distinct differences between spiny neurons and non-spiny neurons. Once incorporated into the network, adult-born neurons maintain significant levels of structural dynamics. This structural plasticity is local, cumulative and sustained in neurons several months after their integration. Thus, I provide a new experimental system for directly studying the pool of regenerating neurons in the intact mammalian brain and suggest that regenerating neurons form a cellular substrate for continuous wiring plasticity in the olfactory bulb.

Requirements of a dieless wire drawing system

Abstract Dieless wire drawing involves the initiation of a localized plastic zone within a constantly tensioned wire. The heat affected zone experiences a temporary reduction in its flow stress. A uniform reduction in cross-sectional area can be initiated by controlling the stability within this region. In-line cooling and subsequent tempering devices enable this continuous process to produce a net finished product with one pass. However, process instability has always been the key identifiable reason for its commercial failure. Recent innovations in data acquisition and motion control have led to a renewed interest in this novel process. This paper outlines the concepts that need to be considered when designing, manufacturing and instrumenting a continuous dieless wire drawing system with flow stability as the primary consideration. Deliberation is given to process parameters and using a kinematic analysis; the key control variables are identified.

High transmittance left-handed materials involving symmetric split-ring resonators

We present theoretical and experimental results for a new design of highly symmetric, multigap split-ring resonators (SRRs), as well as for left-handed materials of a broad and high transmittance left-handed band, achieved by combining those symmetric SRRs with continuous wires. Studying in detail, both theoretically and experimentally, our proposed symmetric SRRs, we proved that they avoid the electric field excitation of the magnetic SRR resonance; thus they are appropriate for the creation of two-dimensional and three-dimensional left-handed materials. Finally, we propose critical design rules for the development of low-loss and broad-band left-handed materials.

Non-left-handed transmission and bianisotropic effect in aπ-shaped metallic metamaterial

A $\ensuremath{\pi}$-shaped metallic metamaterial (geometrically, a combination medium of C-shaped resonators and continuous wires) is proposed to numerically investigate its transmission band near the resonant frequency, where otherwise it should be a negative-permeability (or negative-permittivity) stop band if either the C-shaped or continuous-wire constituent is separately considered. However, in contrast to the left-handed materials (LHMs) composed of split-ring resonators and wires as well as other metallic LHMs, this resonant transmission is a non-left-handed one as a result of the intrinsic bianisotropic effect attributed to the electrically asymmetric configuration of this $\ensuremath{\pi}$-shaped metamaterial.

연속된 와이어를 이용한 다층 PCM의 제조방법 및 특성 평가

연속된 와이어를 이용한 다층 PCM의 제조방법 및 특성 평가

Highly efficient dipole antenna with planar meta-surface

The radiation performance of a dipole antenna closely placed to a planar meta-surface based on parallel short dipoles and continuous wires is presented. Owing to the uniform illumination of the superstrate, an enhancement of gain up to 6.8 dBi is obtained, the thickness of the whole system being 0.135λ0 and the aperture efficiency 82%.