Prototyping rapid

Rapid prototyping or stereolithography or three-dimensional object curing is a photochemical process used to produce solid three-dimensional objects, such as models, masters, or patterns with any shape directly from a design. 

Printing line with UV curing lamps. PS, printing station UV, UV curing lamps. (Courtesy of 1ST Metz.) 

The software sends location information to the laser/mirror system, which then directs light energy to specific regions of a thin layer of photoreactive chemical (UV curable formulation) present on a movable platform in the reservoir. Simultaneously, the information package directs the system to lower the platform slowly with the cured slice of the object into the reservoir.  

The resin systems used in this process are mainly based on methacrylates and acrylates and epoxies.The selection of the resin system depends on the required physical properties. 

The field of rapid prototyping involves the production of prototype articles and small quantities of functional parts, as weU as structural ceramics and ceramic shell molds for metal casting, directly from computer-generated design data (18). 

Two well-known methods for rapid prototyping include (18)  

A liquid binder three-dimensional printing process. 

These techniques are similar as both use layering techniques to build three-dimensional articles. 

Both methods form successive thin cross sections of the desired article. The individual cross sections are formed by bonding together adjacent grains of a granular material on a generally planar surface of a bed of the granular material. 

An important application of CAD technology has been in the area of rapid prototyping. Physical models traditionally have the characteristic of being one of the best evaluative tools for influencing the design process. Unfortunately, they have also represented the most time- 

In order for CAD applications to run across systems from various vendors, four main formats facilitate this data exchange IGES (Initial Graphics Exchange Specification), STEP (Standard for the Exchange of Product Model Data), DXF (Drawing Exchange Format), and ACIS (American Committee for Inter-operable Systems) 

developed by Autodesk, Inc. for AutoCAD software, is the de facto standard for exchanging CAD/CAM data on a PC-based system. Only 2-D drawing information can be converted into DXF, either in ASCII or in binary format. 

The ACTS modeling function N a set of software algorithms used for creating solid-modeling packages. Software developers license ACTS routines from the developer Spatial Technology Corp. to simplify the 

There is a consensus that such heterogeneity is the rule, rather than the exception, even within one company or one department and today s collaboration worldwide and cross the boundaries of companies and networks. A variety of techniques and software to share information are now available. They include  

Acura SI 40 epoxy resin, (a) Machined notch, with brittle fractures, (b) Stereolithography notch (Hague, R. et o/., J. Mater. Set., 39, 2457, 2004) with kind permission of Springer Science and Business Media. 

Rapid prototypes do not have the mechanical durability of the thermoplastic product, but are adequate to assess the product appearance, assembly and some mechanical properties. The CAD instructions, used for making the prototype, can also be used to machine the alloy steel blocks for injection moulding, reducing the production time. 

An elastomeric stamp or mold with relief structures on its surface is the key to soft lithographic techniques (see Sect. 3.2). As a result, the utility of these techniques is often limited by the availability of appropriate masters. In general, the masters are fabricated using photolithography. Chrome masks are available commercially from custom fabricators,but the time required for vendors to produce a chrome mask from a design presented in a computer aided design (CAD) file can be weeks, and they are expensive ( 300 per square inch for features larger than 20 pm, and 500 - 1000 per square inch for features between 1 and 

20 im). The time and expense involved in generating chrome masks are barriers to the use of photolithography by chemists and biologists and have limited the use of microfabrication in these fields. 

They are flexible, and can be used to pattern non-planar substrates. 

They are thin, and can be stacked on top of one another to generate new types 

After the patterns on these polymer films are transferred into photoresist films coated on silicon substrates using photolithography, the developed photoresist patterns can serve as a master to make the required PDMS stamps. By combining this method of rapid prototyping with soft lithographic techniques, we can fabricate patterned microstructures of polymers and metals within 24 h of the time that the design is completed. Rapid prototyping makes it possible to produce substantial numbers of simple microstructures rapidly and inexpensively. 

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Rapid Prototyping Model of Power Saw Cabinet Part as seen in Figures 6 and 7. Using the Stereolithography technique the part was modelled from a polymere. 

A prototype is a 3-D model suitable for use in the preliminary testing and evaluation of a product (also used for modeling a die, mold and other tool). It provides a means to evaluate the product s performances before going into production. The ideal situation is for the prototype to be the actual product made in production. However machining stock material and using rapid prototype techniques can make prototypes (Chapter 4, BOOK SHELVES). 

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. 

Entries on new materials, including re-cyclate plastics, fullerenes, hard-surfaced polymers, dendrimers, transflective materials, rapid prototyping materials, silicone nitride, supercritical fluids, bulk molding compounds, conversion coatings, folic acid, replacements for chloro-fluorocarbons ... 

Fuges, C., Rapid Prototyping-A Journey, Not a Destination, MoldMaking Tech., Feb. 2000. 

Muller RP, Phihpp DM, Goddard WA. 2003. Quantum mechanical-rapid prototyping apphed to methane activation. Top Catal 23 81-98. 

Research users need full access to the functional elements of the spectrometer system and require the most efficient and flexible tools for MR sequence and application development. If the measurement methods delivered with the software do not adequately address the specific investigational requirements of a research team, modem NMR software is an open architecture for implementing new and more sophisticated functionality, with full direct access to all hardware controlling parameters. After evaluation, the new functionality can be developed with the help of toolbox functions that allow rapid prototyping and final builds, to enable the new sequence to be executed by non-experienced personnel and then used in routine applications. These toolboxes provide application oriented definitions and connect to standard mechanisms and routine interfaces, such as the geometry editor, configuration parameters or spectrometer adjustments. 

Anderson J.R., Chiu D.T., Jackman R.J., Chemiavskaya O., McDonald J.C., Wu H.K., Whitesides S.H., Whitesides G.M., Fabrication of topologically complex three-dimensional microfluidic systems in PDMS by rapid prototyping, Anal. Chem. 2000 72 3158-3164. 

Pique, A. Chrisey, D. B. 2001. Direct-write electronics for rapid prototyping applications. In Sensors, Electronics and Integrated Power Sources. Academic Press, New York. 

Napadensky, E. 2005. Ink-jet 3d printing of photopolymers materials An emerging rapid prototyping technology. Proceedings—RadTech Europe 05 UV/EB 2 193-197. 

Code generation is nevertheless a useful facility, at least for creating prototypes. It is easy to take the packages from your business analysis and turn them into the skeleton of a rapid prototype. 

Rapid Prototyping Preparation ofa VA prototype of external casing Technician ... 

Figure 12.8-8. Using computer-aided design software and rapid prototyper to create product from a design blueprint.

The primary differences, then, between development of expert systems and more traditional software engineering are found in steps one and two, above. First, the problems chosen will involve symbolic reasoning, and will require the transfer of expertise from experts to a knowledge base. Second, rapid prototyping, the "try it and see how it works, then fix it or throw it away" approach will play an important role in system development. 

Another coupling method, i.e. cross-linking or entrapment in polymeric films, which has been used to create a more permanent nucleic acid surface, is described in some chapters (e.g. conductive electroactive polymers for DNA immobilization and self-assembly DNA-conjugated polymers). One chapter reviews the basic characteristics of the biotin-(strept)avidin system laying the emphasis on nucleic acids apphcations. The biotin-(strept)avidin system can be also used for rapid prototyping to test a large number of protocols and... 

Harrison C, Cabral J, Stafford CM, Karim A, Amis EJ (2004) A rapid prototyping technique for the fabrication of solvent-resistant structures. J Micromech Microeng 14 153-158... 

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