3D Printing and Prototyping

3D printing, or computer-aided additive manufacturing, creates physical objects from digital files by generating very small layers of material that build up to a final [Page 769]form. 3D printing is a technological innovation that differs from older computer-controlled subtractive manufacturing techniques where objects are shaped by removing material from large pieces. With a 3D printer, one can make almost anything, including jewelry, circuits, food, and even artificial organs. In educational settings teachers can use 3D printers to help students create and design a variety of educational objects such as recreations of historical artifacts, complex art forms, scientific models, and even cheaper versions of lab materials. 3D prototyping involves iteratively making three-dimensional solutions to problems, finding places for improvement, and then refining and revising solutions. 3D printing and prototyping has been used in both undergraduate and graduate engineering education contexts. Recent innovations in technology, as well as a growing emphasis on science, technology, engineering, and mathematics (STEM) in precollege and informal settings, demonstrate the potential that 3D printing and prototyping can have in many educational contexts. This entry first provides an overview of the development of 3D printing technologies and elaborates on current uses in educational settings. It then discusses the future potential of 3D printers as well as barriers to integration with educational settings.

3D printing can be thought of as an extension of inkjet printing but instead of printing a single layer of ink, 3D printers print material. A 3D printer creates objects by adding material in successive layers, gradually building up the object in three dimensions by placing what are essentially two-dimensional cross-sections of the object on top of each other. Voids can be created in the object by adding a different support material that is later removed by post processing, such as using chemicals to dissolve the support material while leaving the rest of the object intact. This gives a 3D printer the capability to produce complex multipart assemblies that are fully assembled, something that would be difficult to achieve and require multiple steps through other means.

Users create objects to be 3D printed through computer-aided design (CAD) software. CAD software allows users to design and create virtual objects. Common examples of CAD software include AutoCAD, Pro-Engineer, and Google SketchUp. Once a user creates a design, the virtual object is converted into a standard computer format (such as the stereolithography, or STL, de-facto standard format) and processed by the 3D printer.

Rapid prototyping with 3D printing generally refers to the ability to make models of final designs quickly and with high quality. Although many fields have used rapid prototyping of objects as part of design processes before the invention of the 3D printer, rapid prototyping technologies such as 3D printers enable complex designs to be quickly fabricated for high resolution testing and revision. Instead of waiting weeks or months for prototypes, similar if not higher quality objects can be printed in days or hours.

Contemporary 3D printing has roots in industrial manufacturing and rapid prototyping. Prior to 3D printing, parts were usually made via subtractive methods (as opposed to the additive method utilized by a 3D printer), such as milling or grinding, which reduced larger starting pieces of material to form shapes. 3D printing first arose in the 1980s in industrial settings, and, as such, was cost prohibitive for regular consumers. Now, in the 21st century, hobbyist and home models of 3D printers are available at a price that many individuals and educational institutions can afford. These include machines from open-source projects such as RepRap and Fab@Home, as well as commercial offerings such as those from Afinia and Cubify. While not as fast or robust as an industrial model costing tens of thousands of dollars (or more), these hobbyist and home models (costing a few thousand dollars or less) allow regular consumers the ability to engage in the same rapid prototyping and custom fabrication that were previously only available in industrial settings. Designs created for the at-home 3D printer can also be processed by an industrial 3D printer, giving individuals the capability to send their designs out to an industrial 3D printer for mass production. Companies now offer 3D printing services for individuals who want to create their own custom 3D printed objects but do not have access to a 3D printer.

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