How does 3D printing work?

Answered by Wenchao Zhou.

3D printing, also known as additive manufacturing, is a process of joining materials to make objects from models, usually layer upon layer. The core idea of joining materials together to make objects is ancient. Some examples include various adhesives, bricks and mortar for building houses and even Lego blocks.

3D printing digitizes this idea by using a computer to control the joining of materials based on the digital model. The first 3D-printing technology, called stereolithography, was invented by Charles Hull in 1984. Hull worked for 3D Systems. His technology used a computer to control the scanning of a laser to selectively solidify a liquid resin one layer at a time to form a 3D object. After that, more than a dozen 3D printing processes were invented based on different mechanisms to join materials. One example is process called fused deposition modeling, which uses a heated nozzle to extrude and join plastic filaments together. This is the process used by most consumer-grade 3D printers.

The primary benefit of 3D printing is manufacturing freedom. Because it joins the material units together from ground up – similar to building a Lego structure – it can theoretically make complex geometries, unlike machining and other traditional manufacturing techniques that are limited by the geometrical constraints of the machine tools. The dream is that one day scientists and engineers will be able to join materials together atom by atom, which will achieve ultimate manufacturing freedom.

Joining materials together bit by bit is a painfully slow process, which ramps up manufacturing costs. Although computers can do it relatively fast, and significant progress has been made during the past decades, 3D printing is still not comparable to traditional manufacturing in the context of mass production. Depending on the application, it is about 10 to 100 times slower that traditional manufacturing. One solution that’s currently being developed in my laboratory, the AM3 Lab here at the U of A, is to have thousands of mobile 3D printers working together, but autonomously, to speed up and reduce manufacturing costs, as illustrated in the picture above.

Wenchao Zhou

Wenchao Zhou

Assistant Professor of Mechanical Engineering

Wenchao Zhou is an assistant professor of mechanical engineering and director of the Advanced Manufacturing, Modeling and Materials Lab, or AM3 Lab, which develops next generation 3D printing technologies. His research focuses on 3D printing and robotics. He holds the 21st Century Professorship.

About The Author

Matt McGowan writes about research in the College of Engineering, Sam M. Walton College of Business, School of Law and other areas. He is the editor of Short Talks From the Hill, a podcast of the University of Arkansas. Reach him at 479-575-4246 or

University Relations Science and Research Team

University Relations Science and Research Team

Matt McGowan
science and research writer

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