Laser Microfabrication Techniques

Laser microfabrication technique is also commonly present in most of the microfluidic laboratories. This technique is growing very fast recently and is contributing toward 

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Discusses many microfabrication techniques, including deposition, photolithography, etching, annealing, liquid-phase photopolymerization, micromolding, electroplating, laser-assisted processes, and more... 

Laser ablation has become a versatile machining technique, particularly in machining of microstructures. Although there are other microfabrication techniques, such as lithography, wet chemical and reactive ion etching, laser ablation provides a direct and fast structuring method. For some materials, laser ablation seems to be the only... 

New techniques are being applied to develop miniaturized sensor arrays such as screen printing for thick film and electron beam evaporation, thermal vacuum deposition, and pulsed laser deposition for thin-film technique. Microfabrication techniques were used to prepare a sensor array for use in a voltammetric e-tongue by depositing gold (Au), platinum (Pt), iridium (Ir), and rhodium (Rh) on a silicon wafer. 

Generative laser-based techniques for 3D microfabrication are widely used and their importance is likely to grow as the need for rapid prototyping and manufacturing as well as customization of a variety of products is increasing. 

Figure 10.31 shows the picture of a laser micromachining center. In laser microfabrication, a highly directional light beam, that is, laser, is focused close to diffraction-limited spot size, which is incident on the matter to be machined. The availability of pulse laser at higher repetition rates adds to the capability of laser-based microfabrication. This technique avoids a lengthy and wasteful multistep approach based on lithography. 

D microfabricated reactor devices are typically made by fabrication techniques other than stemming from microelectronics, e.g. by modern precision engineering techniques, laser ablation, wet-chemical steel etching or pEDM techniques. Besides having this origin only, these devices may also be of hybrid nature, containing parts made by the above-mentioned techniques and by microelectronic methods. Typical materials are metals, stainless steel, ceramics and polymers or, in the hybrid case, combinations of these materials. 

In terms of beam delivery, the DLW method is based on optical microscopy, confocal microscopy [4,6,13] and laser tweezers [14] (for reviews on laser tweezers see [ 15,16]). These techniques allow for a high spatial 3D resolution of a tightly focused laser beam with optical exposure of micrometric-sized volumes via linear and nonlinear absorption. In addition, mechanical and thermal forces can be exerted upon objects as small as 10 nm molecular dipolar alignment can be controlled by polarization of light in volumes of with submicrometric cross-sections. This circumstance widens the field of applications for laser nano- and microfabrication in liquid and solid materials [17-22]. 

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