What is 3D printing?

3D printing builds three-dimensional objects based on instructions in computer files.

I guess this isn’t a typical office printer?

Nope, this kind of printer works differently. Instead of putting down a single layer of ink on paper as regular printing does, 3D printing adds layer after layer of a material—such as plastic, metal, ceramic, or cells—until a desired object is built.

Because objects are built by adding material (rather than by taking it away as in machining, or reshaping it as in molding or forming), 3D printing is also known as “additive manufacturing.”


And 3D printing is good because…?

3D printing is spurring breakthroughs in many industries. Some of its benefits:

  • Inventors and designers can build and test prototypes of new products quickly and cheaply.
  • Errors in a product’s design can be caught and fixed before manufacturers invest in expensive mass-production equipment.
  • Replacement parts can be built swiftly on an as-needed basis.

What is it useful for?

Some of the most exciting applications are emerging in medicine and space exploration. It’s being used to create prosthetics and implants tailored to a person’s body. For example, Walter Reed Army Medical Center is 3D printing cranial implants for soldiers with head injuries. Made out of titanium, the implants are customized to each patient’s body and injury.

Someday it may even be possible to print human organs such as livers and kidneys using living cells, which will be useful for research and transplants. Printing a complex, functional organ such as a heart or a liver is still beyond reach, but researchers are making progress. For example, they have:

  • constructed strips of liver cells that can be used to test experimental drugs, and
  • experimented with printing skin or heart cells that could be used for skin grafts or to repair damage from heart attacks.


You mentioned 3D printing helps in space?

Yes, think about it. When most people face an unexpected home appliance breakdown, the problem can usually be solved with a trip to the hardware store or a call to a repair person. If you’re an astronaut, sudden equipment breakdowns obviously pose bigger logistical problems.

Many hardware failures on the International Space Station involve plastics and other materials that could be repaired using 3D printing. Instead of waiting for spare parts to be sent up from Earth, astronauts could print parts as needed.

Printable human organs? Maybe someday. Astronaut Christina Koch works with a 3D biological printer on the International Space Station. Human organs, with their small and complex parts, have been difficult to print in Earth’s gravity. Printing organ-like tissues in microgravity may be a step toward printing whole human organs in space. Credit

But this is still science fiction, right?

Actually, it’s not. NASA and the private-sector company Made In Space have been experimenting with 3D printing on the space station since late 2014, and they report that the technology has worked in microgravity similarly to how it works on Earth. During one test, digital files with instructions to make a ratchet tool were uploaded to the space station and an astronaut had the completed tool in hand 2 hours later.

The capacity to manufacture objects as needed could yield huge benefits for possible future space missions.

Commander “Butch” Wilmore with a 3D-printed ratchet wrench made on board the International Space Station. No trip to the hardware store required. Credit

What are the challenges?

Significant scientific and engineering questions remain. More testing and development are needed to understand how 3D printing works in the harsh environmental conditions of space. Some part designs are particularly challenging to print. Researchers are working to improve manufacturing precision and have developed techniques to refine 3D printed parts, even after they’ve finished printing.

Material properties can also change during the 3D printing process, which can result in unexpected variability and unreliability. Researchers are developing detailed mathematical and computational models to better understand these material variations.

Can I try this at home?

The 3D printing machines used in some industrial settings are sophisticated and expensive, but you can buy simpler models for a few hundred dollars or less and use them to make toys, tools, and other household objects.

Know it all? Prove it.