Insoles by companies like SOLS aren't the only products getting the 3-D printing treatment. Here's a look at other health care innovations.

Orthotics

Beyond insoles, medical tech start-ups are using 3-D scanning and printing technologies to quickly create orthotics. The UK-based Andiamo, which was recently named a "One to Watch 2016" by Richard Branson, makes specialized braces for children in just 48 hours.

Prosthetics

3-D-printed prosthetics are providing amputees with fast, low-cost options, especially those in developing and poor countries. Notable names in the arena include the Indiegogo-funded, Bristol, England-based Open Bionics, which makes a bionic hand; the South Africa-based Robohand, which develops prosthetics including hands, fingers and arms; and 3D LifePrints, which manufactures 3-D printed arms and hands, as well as models of arms and legs that can cover prosthetics.

Organs

Scientists are developing ways to print artificial organs, such as kidney and liver structures. 3-D printed models of organs like hearts are also being used to help doctors prepare for surgeries. Organs printed from living tissue isn't a reality yet, but in recent progress toward that effort, researchers at the University of Florida in Gainesville have created a gel comprised of an acrylic acid polymer that would help support complex structures, like organs.

Bone repair

Metal pins or screws are often used to treat broken or fractured bones, but they may cause problems like infections or arthritis. Researchers at the University of Pittsburgh McGowan Institute for Regenerative Medicine are using 3-D printing to create an alternative. They've developed magnesium and iron alloys that can be printed to perfectly fit patients and help heal bones in place of pins or screws before eventually dissolving.