Films delamination

Film Delamination Most sensors have a film or membrane used as a sensing layer and/or a biocompatible layer. When this film is not attached properly or degrades, it can fail and delaminated from the electrode surface, causing the sensor to lose function through increased mass transfer resistance, diminished electron transfer, and/or its ability to deter the foreign body reaction.31... 

Solid-solid Adhesion Solid suspension, adhesion, cohesion, corrosion, passivation, epitaxial growth, wear, friction, diffusion, thin films, delamination, creep, mechanical stability, durability, solid state devices, blend and alloy, charge transfer, nucleation and growth abrasion... 

To increase the wear resistance of surfaces, silicon and metals are often coated with a hard nitride, carbide, boride, or oxide film. Nanoindentation and fracture simulations have been used extensively to elucidate failure mechanisms of these typically more brittle surfaces, which include crack propagation and film delamination. Considerable attention has also focused on nanocomposite materials, which possess nanocrystalline inclusions in an otherwise amorphous matrix. The nanocrystalline component is sufficiently small to preclude the formation of stable dislocations, and thus provide a higher hardness. 

Ambrico, J.M. and Begley, M.R., The role of flaw geometry in film delamination from two-dimensional interface flaws along free edges, Engineering Fracture Mechanics 2003,70,1721-1736. 

Nanoindentation is a powerful technique because the shape of the load-displacement curve can be used to identify effects such as phase transformations, cracking, and film delamination dining indentation. It is also important in studying the mechanical properties of nanomaterials, such as carbon nanotubes. There is reference now to a picoindenter, which is a combination of a nanoindenter and an atomic force microscope (AFM). 

The high compressive stresses in hard a-C H and ta-C films (up to 10 GPa, depending on the deposition conditions, especially the bias voltage) [79] frequently lead to film delamination and thus limit the attainable film thickness. For many years thicknesses of more than 1-2 pm could not be realized on technically relevant substrates like steel, hardmetal or glass. Considerable improvements were achieved by applying intermediate layers consisting of aSi H [80], metals (Al, Ti, Ni) [81, 82], or multilayers (Ti-TiCN-TiC) [83], for example. For the characterization of... 

Scratching takes place when the indenter is dragged along the surface after indenting the coating. Heavens noted that the film would debond at a critical load as the indenter was pressed down onto the coating. This is a much more complex mode of film delamination which can give useful test data but is difficult... 

As was noted before, the kinetics of palladium-based sensor response is limited by bulk diffusion. This means that response at room temperatures cannot be fast. Ding et al. (2006) proposed to resolve this problem by forming nanoporous palladium thin films using anodic alnminum oxide (AAO) templates. Ding et al. (2006) have found that porons films had lower detection limit and faster and sharper response than the dense palladium films. Ding et al. (2006) believe that the film delamination problem may be alleviated in the nanoporous structures as well. 

Jensen, H. M. (1993), Energy release rates and stability of straight-sided, thin-film delaminations, Acta Metallurgica et Materialia 41, 601-607. 

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