Explainer: What is 3-D printing? | Science News for Students

Explainer: What is 3-D printing?

New devices may one day allow people to manufacture almost anything from their home or office
Sep 30, 2014 — 7:30 am EST
illustration of moon base

NASA and the European Space Agency both believe 3-D printing might be used to build a base on the moon. This illustration shows what such a base might look like.


Imagine that the printer hooked up to your home computer could make anything. Lost your toothbrush? No problem. Print it. Need new shoes, a new dress, new cleats? Just instruct your computer to tell that machine what style and size you want. Then print, print and print some more.

Already, some companies are figuring out how to print cells as the first step in creating a new organ for transplanting into people. One company has just printed most of a working electric car.

In a few years, 3-D printing could drastically change the world of manufacturing. Already, creative people — they call themselves makers — have formed communities to share computer files that give the directions for making their novel creations

According to legend, the French sculptor Auguste Rodin once explained: “I choose a block of marble and chop off whatever I don’t need.” This means he used subtraction to sculpt his creations. 3-D printing does the opposite: It adds layers, one at a time, to build something from the bottom up. That’s why some engineers refer to 3-D printing as additive manufacturing.

For 3-D printing, someone must create a computer file that describes a desired object in three dimensions. This blueprint includes the size, shape and color of the thing to be printed. Then someone tells the computer to digitally “slice” that object into virtual slivers. The printer then builds each slice, one thin layer at a time.

Some printers spit out metal. Others spray a liquid that will harden into plastic. Some manufacturers are using special printers to spray out chocolate, cheese or other foods to make custom products. In 2013, one biomedical research company used plastic to 3-D print 75 percent of a man’s skull, which was then surgically implanted into the patient.

The European Space Agency has begun research to see if it can “print” a moon base using lunar soil. NASA, the American space agency, is investigating the idea of using 3-D printing to create food for astronauts on deep-space missions.

Power Words

additive manufacturing    This process of creating solid objects by depositing material, micro-layer by micro-layer (or slice by slice) from the bottom up. It’s an explanation for how 3-D printing works.

cell The smallest structural and functional unit of an organism, typically too small to see with human eyes.

digital   (in computer science and engineering) An adjective indicating that something has been developed numerically on a computer or on some other electronic device, based on a binary system (where all numbers are displayed using a series of only zeros and ones).  

engineering   The field of research that uses math and science to solve practical problems.

maker   A term used to describe people who are do-it-yourselfers, making things they want and need, rather than buying commercial versions of products (everything from fabric and beer to furniture and tools). Many makers are now turning to 3-D printers to create items when and where they’re needed.

manufacturing  The making of things, usually on a large scale.

organ     (in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary makes eggs, the brain interprets nerve signals and a plant’s roots take in nutrients and moisture.

tissue  Any of the distinct types of material, comprised of cells, which make up animals, plants or fungi. Cells within a tissue work as a unit to perform a particular function in living organisms. Different organs of the human body, for instance, often are made from many different types of tissues. And brain tissue will be very different from bone or heart tissue.

transplant    In medicine, the replacement of tissue or an organ with that from another organism.

three-dimensional (3-D) printer   A machine that takes instructions from a computer program on where to lay down successive layers of some raw material to create a three-dimensional object.

three-dimensional (3-D) printing    The creation of a three-dimensional object with a machine that follows instructions from a computer program. The computer tells the printer where to lay down successive layers of some raw material, which can be plastic, metals, food or even living cells. 3-D printing is also called additive manufacturing.

virtual  Being almost like something. An object or concept that is virtually real would be almost true or real — but not quite. The term often is used to refer to something that has been modeled — by or accomplished by — a computer using numbers, not by using real-world parts. So a virtual motor would be one that could be seen on a computer screen and tested by computer programming (but it wouldn’t be a three-dimensional device made from metal).

Further Reading

K. Kowalski. “Fashioning inks to print ‘tissues.’Science News for Students. Aug. 12, 2014.

B. Brookshire. “A 3-D printer prints a better life.” Science News for Students, March 6, 2014.

B. Brookshire. “A 3-D printer in every classroom.” Science News for Students, November 14, 2013.

S. Ornes. “'Print' almost anything.Science News for Students. April 28, 2013.

S. Ornes. “The return of a king.Science News for Students. Feb. 14, 2013.

D. Mackenzie. “Cool Jobs: Math as entertainment.” Science News for Students. Dec . 19, 2012.

See all kinds of 3-D printing projects at the web site of Materialise, a company at the forefront of the technology.

Ready to make your own 3-D printer? Download plans from Cornell University's Fab@Home project.