" " A 3-D printed heart made from human tissue is processed at Tel Aviv University, Israel in 2019. Israeli scientists have, for the first time, created an entire heart with cells, blood vessels, ventricles and chambers using a 3-D printer. Amir Levy/Getty Images

Not too long ago, the idea of 3-D printing – creating three-dimensional objects using machines that add layers of material on top of one another – seemed novel. If you say you're going to print something from your computer, most people still think of two-dimensional printing, putting toner or ink on a piece of paper. Now, although many people may not have experienced 3-D printing themselves, they may very well know what you're talking about. And 3-D printers have become affordable enough to start showing up in homes, makerspaces and classrooms.

3-D printing uses a family of manufacturing technology called additive manufacturing (AM). AM is the means of creating an object by adding material to the object layer by layer. AM is the current terminology established by ASTM International (formerly the American Society for Testing and Materials) [source: Gibson, et, al.]. Throughout its history, additive manufacturing in general has gone by various names: stereolithography, 3-D layering and 3-D printing. This article uses the term 3-D printing because it's more well known.



You can see some of the basic principles behind AM in caves; over thousands of years, dripping water creates layers and layers of mineral deposits, which accumulate to form stalagmites and stalactites. Unlike these natural formations, though, 3-D printing is much faster and follows a predetermined plan provided by computer software. The computer directs the 3-D printer to add each new layer as a precise cross-section of the final object.

Additive manufacturing and 3-D printing specifically, continues to grow. Technology that started out as a way to build fast prototypes is now a means of creating products for the medical, dental, aerospace and automotive industries. 3-D printing is also crossing over into toy and furniture manufacturing, art and fashion.

This article looks at the broad scope of 3-D printing, from its history and technologies to its wide range of uses, including printing your own 3-D models at home. First, let's take a look at how 3-D printing got its start and how it is developing today.