Fabrication

About: Fabrication is a research topic. Over the lifetime, 20475 publications have been published within this topic receiving 235676 citations.

Fabrication of organic light-emitting diode pixels by laser-assisted forward transfer

Abstract: Fabrication of a polymer light-emitting device was achieved by a laser forward transfer technique using the decomposition of a thin triazene polymer film by a XeCl excimer laser The dry deposition process allows transfer of a bilayer consisting of the electroluminescent polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] covered with an aluminum electrode onto a receiver substrate The soft transfer results in laterally well resolved pixels (≈500μm), whose fluorescence as well as electroluminescence spectra remain unaltered The rectifying and smooth current-voltage characteristics add to the merits of this laser-based transfer method that opens up the possibility of direct-writing heat- and UV-sensitive materials

Fabrication of polarisation-maintaining fibres using gas-phase etching

Abstract: A new fabrication technique for the production of high-birefringence fibres is described. The process is shown to produce fibres with a cross-sectional geometry which is close to the optimum predicted by stress analysis. As a result, fibres with extremely short beat lengths (0.55 mm at a wavelength of 633 nm) have been produced.

Electron Beam Freeform Fabrication: A Rapid Metal Deposition Process

Abstract: Manufacturing of structural metal parts directly from computer aided design (CAD) data has been investigated by numerous researchers over the past decade. Researchers at NASA Langley REsearch Center are developing a new solid freeform fabrication process, electron beam freeform fabrication (EBF), as a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Thus far, this technique has been demonstrated on aluminum and titanium alloys of interest for aerospace structural applications nickel and ferrous based alloys are also planned. Deposits resulting from 2219 aluminum demonstrations have exhibited a range of grain morphologies depending upon the deposition parameters. These materials ave exhibited excellent tensile properties comparable to typical handbook data for wrought plate product after post-processing heat treatments. The EBF process is capable of bulk metal deposition at deposition rated in excess of 2500 cubic centimeters per hour (150 cubic inches per our) or finer detail at lower deposition rates, depending upon the desired application. This process offers the potential for rapidly adding structural details to simpler cast or forged structures rather than the conventional approach of machining large volumes of chips to produce a monolithic metallic structure. Selective addition of metal onto simpler blanks of material can have a significant effect on lead time reduction and lower material and machining costs.

Plasma electrolytic fabrication of oxide ceramic surface layers for tribotechnical purposes on aluminium alloys

Abstract: The problem of technical and economical optimization of the process of micro-arc discharge oxidation of high-strength aluminium for the fabrication of oxide ceramic layers for tribotechnical purposes is considered in terms of experimental design. To estimate the effectiveness of the process, a generalized parameter is used which accounts for oxide mass yield as a principal parameter, and mechanical and geometrical characteristics of the layer as restricting parameters. The methods of chemical weight, scanning electron microscopy, optical and durometric analyses are used. The influence of the silicate–alkali electrolyte composition and the amount of electricity carried through the cell on the layer properties is discussed. The response surface of the generalized parameter is plotted with the aid of desirability functions. The area of regimes corresponding to 2–3 g l −1 KOH and 2–3 g l −1 Na 2 SiO 3 electrolyte composition and (2.50–3.33)×10 3 C m −2 of carried electricity is outlined for the most effective fabrication of uniform oxide layers with 165–190 μm thickness and 18–23 GPa hardness.

Back-contact solar cells and methods for fabrication

Abstract: Methods for fabrication of emitter wrap through (EWT) back-contact solar cells and cells made by such methods. Certain methods provide for higher concentration of dopant in conductive vias compared to the average dopant concentration on front or rear surfaces, and provided increased efficiency. Certain methods provide for selective doping to holes for forming conductive vias by use of printed dopant pastes. Other methods provide for use of spin-on glass substrates including dopant.