Laser rapid prototyping

M. C. Wanke, 0. Lehmann, K. Muller, Q. Wen and M. Stuke, Laser rapid prototyping of photonic band-gap microstructures. Science, 275,1284-1286 (1997). 

Among the above applications, computer-aided manufacturing (CAM) using UV curable resin, generally called laser rapid prototyping, is a new and expanding technology [6-9]. It converts three-dimensional (3D) objects of... 

Fig. 7 Illustration of several types of layered manufacturing technologies, a Laser rapid prototyping using photopolymerizable resin, b powder sintering, c ink injecting and writing and d resin squeezing and writing...

Fig. 8 A laser rapid prototyping system. The writing could be accomplished either by mirror angle scanning or by moving sample stages. The former mechanism is shown here. Three major approaches were utilized to control the longitudinal resolution, a film casting, b surface regulation, and c open surface methods...

To solve this problem, Maruo et al. [10] proposed a two-photon laser rapid prototyping technology, now known as two-photon photopolymerization. In this scheme the laser was directly focused inside a liquid resin droplet and it polymerized the focal point volume by TPA. This technology firstly eliminates the requirement of thin additive liquid film and controls the longitudinal spatial resolution by focal spot size itself, and secondly, it provides the capability of writing arbitrary 3D patterns within the droplet volume, as can be done in 3D laser writing in solid matrix only if the resin viscosity is reasonably high. From this sense, the laser focus functions as a real 3D laser pen. 

Methods are used to produce the more costly rapid prototypes include those that produce models within a few hours. They include photopolymerization, laser tooling, and their modifications. The laser sintering process uses powdered TP rather than chemically reactive liquid photopolymer used in stereolithography. Models are usually made from certain types of plastics. Also used in the different processes are metals (steel, hard alloys, copper-based alloys, and powdered metals). With powder metal molds, they can be used as inserts in a mold ready to produce prototype products. These systems enable having precise control over the process and constructing products with complex geometries. 

Laser-based micromachining processes have been applied to date only on a relatively small scale for manufacturing chemical microdevices (27). This will probably change relatively soon, since rapid prototyping will become more and more important for developing novel microreaction devices. 

Lehmann O, Stuke M (1995) Laser-CVD 3D rapid prototyping of laser driven moveable micro-objects. J Phys IV5 C5-601-606... 

Duty CE, Jean DL, Lackey WJ (1999) Design of a laser CVD rapid prototyping system. Ceram Eng Sci Proc 20 347-354... 

As seen in this brief chapter, the direct-printing process, based on laser printing of layouts on polyester films or wax paper, has the potential to become a powerful technology for the rapid prototyping of microfluidic devices at very low cost, and even a source of low-cost production of disposable devices. This is supported by the fact that the required instrumentation is commonly found at offices and chemistry laboratories. Besides the typical injection and separation channels for electrophoresis, this technology has shown that mixing, preconcentration, clean-up, reactor devices. 

M. F. Jensen, J. E. McCormack, and B. Helbo, Rapid prototyping of polymer microsystems viaexcimer laser ablation of polymeric mould. Lab on a Chip, 4(4), 391-395, 2004. 

Duplication of prototype master models (made by special techniques such as laser stereolithography, laser powder sintering, LOM etc.) in polyurethane or epoxy resins by the vacuum casting process within the scope of rapid prototyping . 

Laser-Based Micromachining, Fig. 2 Schematic of laser micromachining system for rapid prototyped three-dimensional channel netwoiks using a femtosecond laser. The femtosecond laser provides intensities that overcome the ablation threshold at the tightly focused heam waist... 

Figure 2. Growth of microstructures by laser assisted chemical vapor deposition (LCVD). Linear single laser system (A). Goniometer controlled single laser system (B) and complex dual laser system (C). Redrawn from F. T. Wallenberger, Rapid prototyping directly from the vapor phase, Science, 267,1274-1275 (1995).

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