SciTech

How Things Work: 3D printing

For architects, making wooden models of their designs probably requires painstakingly hard work. One first has to cut the wood, glue it or nail it together, and then start with the painting and fine detailing. Making such prototypes of their work is tedious even for artists and engineers. It requires a large amount of time and effort just to make these small models. However, with a new technique, it is possible to create these designs on the computer and then have a model of the design in one’s hands in just a matter of hours. These new machines, aptly called 3-D printers, allow models of objects to be “printed” based on a 3-D design.

3-D printers use simulations created on a computer and produce exact three-dimensional replicas of the simulations. As of now, 3-D printing is used to create models of newly designed products, and this technique has become so refined that the printers are even able to “print” prototypes with moving parts. Considering the fact that building conventional models would require days of painstaking labor, it is hard not to wonder how these printers manage to build something so complicated within a matter of hours.

Although 3-D printers resemble ink jet printers from the outside, their working is quite different. The initial 3-D design of the object has to be created on the computer. A variety of computer-aided design (CAD) software is available for this. The software helps analyze the shape of the object, breaks it down into layers, and determines the shape of each layer. Information regarding the shape of each layer is then sent to the 3-D printer. The printer builds the object by printing individual layers and stacking them one on top of the other. The layers are extremely thin, and according to a paper from the EDUCAUSE Evolving Technologies Committee, thicknesses range from 0.0035 to 0.007 inches. This concept of stacking layers can be used to build objects of virtually any size.

The only limiting factor is the size of the box of the printer — the bigger the box, the larger the object that can be produced. Again, depending on the size of the object that has to be printed, the time taken for the process to be completed varies from anywhere from one to 12 hours. Although this basic concept is the same for all types of 3-D printers, what makes each type unique is the way the layers are produced.

Printers employing the fused-deposition modeling technique build layers using semi-molten plastic. The plastic used is acrylonitrile butadiene styrene plastic and is relatively non-toxic and durable. When the molten plastic comes out of the printer, it sticks to the layer below it as it hardens, and provides a convenient method of fusing the layers together. Since the plastic is molten, supports often need to be used to keep the layers in place, and once the plastic hardens, these are removed.

The other type of printers are the powder-binder printers. The layers are made up of a powder that is similar to loose plaster. A printer head sprays the powder layer with some sort of binding glue and then the next layer is deposited on top. This process goes on until the object is built. The advantage of this method is that a variety of different materials can be used to make the powder. Hence, if one wants to make the model out of a specific material other than plastic, the powder-binding technique can prove to be extremely useful. In fact, according to an article on singularityhub.com, a European company called Shapeways has recently created a printer that can create objects made of stainless steel. With this new development, the range of objects that can be created using such printers has expanded greatly.

Although the capabilities of such systems are tremendous, scientists are constantly trying to make them even better. An article in New Scientist reports that researchers from the University of California at Berkeley are trying to build objects as complex as light bulbs from 3-D printers. The researchers plan to do this by building layers of semiconductor and conductor materials in such a way that the basic circuits are built as a part of the main body of the device. The team has already discovered how to print basic electronic components like transistors and capacitors. If they manage to “print” such a light bulb, they might soon look at more complicated electronics like remote controls, cell phones, and radios.

With such projects in the pipeline, it is evident that this technology holds great prospects for the future. As of now, however, companies are constantly coming up with ways to make 3-D printing more accessible to the general public. Shapeways has come up with a service that enables users to submit their designs online to Shapeways and Shapeways prints out the prototypes for the users at a rather cheap cost. Such novel ideas have allowed this technology to be available for use to nearly everyone.