Laser patterning

Song, S., Singh, A.K., Kirby, B.J., Electrophoretic concentration of proteins at laser-patterned nanoporous membranes in microchips. Anal. Chem. 2004, 76, 4589—4592. 

H. Schmidt, H. Krug, R. Kasemann, F. Tiefensee, Development of Optical Waveguides by Sol-Gel Techniques for Laser Patterning, in SPIE Proc. 1991,1590, 36. 

P.C. Allen, Laser pattern generation technology helow 25 p,m, Proc. SPIE 3334, 460 468 (1998). 

Selective Deposition of Copper onto Laser-Patterned, Etched Teflon Substrates... 

This laser approach three-step approach to patterned Cu deposition on PTFE. Step one is chemical etching of the entire sample with- sodium naphthalenide, a solution step which can be carried out in a fume hood. Step two consists of laser patterning of portions of the etched layer. This step is self reguiatlng and can be carried out in air. Finally, step three can be either Cu CVD or electroless Cu deposition. The Cu CVD reaction giving selective-area nucleation and growth of Cu is carried out in a simple reactor with minimal vacuum requirements. The electroless Cu variation is a solution process extensively used in the electronics industry which can be carried out in an efficient fume hood... 

A KrF excimer laser (Lambda Physik LEXTRA 200, 248 nm, 30 ns fwhm) or a XeF excimer laser (ibid., 351 nm, 30 ns fwhm) was used as an excitation pulse for inducing expansion/contraction dynamics. The fluence was adjusted with partially transmitting laser mirrors, and was monitored shot-by-shot by a photodiode whose output was corrected with a joulemeter (Gentec, ED-200) with an oscilloscope (Hewlett-Packard, HP54522A). A c tral area of the excimer laser pattern with a homogeneous intensity distribution was chosen with an appropriate aperture and then focused onto the sample surface by using a quartz lens (f = 200 mm). Fresh surface of the sample film was used in every measurement. Etch depth was measured by a surface depth profiler (Sloan, Dektak 3). All experiments were done in air at room temperature. 

Laser patterning is another writing technique whereby a laser is used to directly expose or polymerize a material. A common application is stereolithography where a reservoir of UV-curable polymer is selectively exposed to a UV laser to fabricate complex three-dimensional (3D) structures in a layer-by-layer fashion. For each layer, the laser beam traces a cross section of the part on the surface of the UV-curable polymer. Exposure to UV laser solidifies the pattern traced on the resin and adheres it to the layer below. 

Geometrical, Topographical, and Mechanical Cues substrates with (a) microcontact printing, (b) photo-on Stem Cell Fate in a Micro-ZNano-environment, patterning, and (c) laser patterning Fig. 1 Micropatteming of glass or plastic culture... 

For verification of surface or bulk chemistry changes occurring during laser irradiation the UV-VIS, IR and XPS analysis were performed. Fig. 6 gives the UV-VIS optical spectra obtained before and after laser patterning. Peak at the 405 run corresponds to so-called... 

Maser (Charles Hard Townes) The maser (microwave amplification by stimulated emission of radiation) is a laser for microwaves. Discovered later, the laser patterned its name the acronym maser. ... 

Lee HJ, Beattie PD, Seddon BJ, Osborne MD, Girault HH (1997) Amperometric ion sensors based on laser-patterned composite polymer membranes. J Electroanal Chem 440 73... 

Laser patterning can be used in either constructive (e.g., when the laser is used to create structures on the surface) or destructive (e.g., LIRA, when the laser is used to remove material from the surface and restore electron transfer) modes to create biosensors with enhanced sensitivity. In either case, only part of the electrode surface is derivatized with the biological element, leaving a snbstaniial part of the electrode available for facile electron transfer. The effective concentration of the biological element in these patterned structures can be increased by using den-drimer-like chemistries. This more than compensates for the lost surface area available for biomolecules immobilization in the patterned snrface. A combination of these approaches may ultimately provide the ideal amperometric biosensor surface. 

Blatter A, Maillat M, Pimenov SM, Shafeev GA, Simakin AV. (1998) Lubricated sliding performance of laser-patterned sapphire. TribLettA. 237—241. 

Bio-inspired fibrillar adhesives of different dimensions, fa, b) Metallic nanowhiskers, (c, d) Hierarchically branching fibre arrays made of epoxy resin, fe, f) Silicone molds of a laser patterned metal surface, (g, h) Carbon nanotubes, (a-d, g, h Original micrographs, a-d, g, h from Gorb 2010. e, f from Peressadko and Gorb 2004a)... 

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