Multilayer fabrication

In order to achieve the enhanced strength, atomically sharp A IB interfaces are needed for the mechanism proposed by Koehler. The multilayer hlms should be deposited under a relative low temperature in order to avoid the interdiffusion between the layers. Thus, PVD techniques such as evaporation and sputtering deposition are the reasonable methods to fabricate multilayer hlms. There are several ways to achieve the alternate deposition of the composing layers A and hxed substrate position mode, repeated substrate po-... 

Dayen JF, Mahmood A, Golubev DS, Roch-Jeune I, Salles P, Dujardin E (2008) Side-gated transport in focused-ion-beam-fabricated multilayered graphene nanoribbons. Small 4 716... 

Layer-by-layer (LBL) deposition has become one of the major techniques to fabricate multilayer films. It was introduced by Decher in the form of alternate deposition of cationic and anionic polyelectrolytes [56-58]. This so-called electrostatic self-assembly process dominates the research in this area. However, more recently alternative driving forces have been employed, such as hydrogen bonding, coordination bonding, charge-transfer interactions, and covalent bonding. Since this review concerns the formation, functionaliza-... 

Figure 2. Process sequence for fabricating multilayer Cu/polyimide structures.

M. Ferreira, J.FI. Cheung, M.F. Rubner, Molecular Self-Assembly of Conjugated Polyions - A New Process for Fabricating Multilayer Thin Film Heterostructures , Thin Solid Films, 244, 806 (1994)... 

Complex formation occurs in MeN02 solution and the solution is then applied to the surface to be coated. Washing with water removes the Lewis acid leaving a thin film of the photosensitive pigment. The Lewis acid pigment solubilization (LAPS) technique has been used to fabricate multilayer photoconductors and appears to have a promising technological future. 

PVDF films have been coextruded " to fabricate multilayer films. The specifications of the main and satellite extruders are listed in Table 6.11 and illustrated in Fig. 6.27. In one construction, the top layer consisted of 60% by weight PVDF and 40% by weight of polymethylmethacrylate. The alloy had a melt viscosity of 18,200 poise at a temperature of... 

A new slide-off transfer printing method of fabricating multilayer sensors is shown in Figure 1.6. Typically, the oxide films were separated from the mount paper by soaking them in water before they were transferred on the alumina substrates. After that, they were printed with interdigitated Pt electrodes (the gap between electrodes was... 

The joint use of a Whiter I concentrator based on multilayers to focus low energy (<40 keV) X-rays and a Bragg concentrator like HAXTEL to focus higher energy X-rays appears a possible telescope configuration that efficiently focuses X-rays in a broad energy band (from 1 keV to about 200 keV). A replication technique to fabricate multilayer mirrors is currently investigated, that would render feasible a Wolter I multilayer concentrator... 

The prime function of adhesives is to mechanically attach or bond devices, components, heat sinks, wire, connectors, and other parts onto a circuit board or an interconnect substrate. Adhesives are also used as pastes or films to attach lids in sealing cavity packages and as dielectric films in fabricating multilayer interconnect substrates. The most important consideration in obtaining a reliable adhesive bond is the ability of the adhesive to flow and wet the surfaces. For a reliable bond, strong adhesion to both surfaces and strong cohesion within the adhesive are necessary. 

The spray head configuration is an interesting aspect of EHDA. The nozzle varies from a simple hypodermic needle of different diameters to highly technologically advanced multiplex nozzles (Figure 22.8). The coaxial needle shown increases the number of centered nozzles to four and is mainly used to fabricate multilayer spheres. In coaxial setups, the most commonly used is the coaxial two-capillary nozzle used to fabricate core-shell spheres (capsules). The inner needle is supplied by a solution of active substance and the outer needle is filled with shell material.In this process, parameters are used as adjusting switches to control the diameter of the capsules, thickness of the shell, and number of inner cores. The two solvents used in the coaxial setup are immiscible and wettable, and the inner one has a higher surface tension. 

Apart from polyplexes, various nanoscale assemblies of cationic polysaccharides are also proposed to promote the surface-mediated delivery of DNA to cells. These approaches are classified into one of two broad categories (i) methods based upon the physical adsorption of preformed polyplex on polymeric surfaces like PLGA or collagen films and these polyplex functionalized films promoted surface-mediated transfection of cells in vitro and in vivof (ii) methods for layer-by-layer adsorption of DNA and cationic polymers on surfaces to fabricate multilayered thin films. Recently, degradable carbohydrate-based nanogels were proposed for codelivery of pDNA and therapeutic proteins. These systems were designed to possess stimuli-sensitive characteristics where the temperature-sensitive property of nanogels allowed the facile encapsulation of biomaterials, while... 

M. Ferreira, J. FF. Cheung, M. F. Rubner, Molecular self-assembly of conjugated polyions - a new process for fabricating multilayer thin-film heterostructures, Thin Solid Films 1994, 244, 806. 

An alternative approach concerns the preparation of multilayer films in which each layer has different refractive indexes. Li et al. [107] fabricated multilayers with an increasing refractive index from the top to the bottom of the film. They prepared blends of BCP/homopolymers (PS-b-PMMA/PMMA). They used an octadecyltri-chlorosilane-modified glass substrate, and a mixture of solvents made the PMMA domains form a gradient distribution in the vertical direction of the entire micro-phase-separated film. This unique behavior allows, upon removal of PMMA, to obtain porous PS-based structures with variable porosity in the vertical direction (Fig. 6.17). Later, the authors investigated further the parameters [total degree of polymerization (AO, the volume fraction of the PMMA block (/pmma). the weight percentage of the homopolymer, and the solution concentration] that direct the structure formation and related them with the broadband antireflection properties [108]. 

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