Open-source communities have been helping each other print parts for 3D printers with 3D printers. But what can you do with a 3D printer once you have it? One family found a way to print a kind of exoskeleton for their daughter. 

This super-sweet toddler, whose name is Emma, has a congenital disorder that means she doesn’t have the muscle strength to lift her arms by herself. But hey, no big deal — this robot exoskeleton can do it for her. And because it’s 3D-printed out of inexpensive, lightweight plastic, replacement is no big deal when she outgrows it (or if she breaks a part). As far as I’m concerned, this singlehandedly justifies the existence of 3D printing.

The 3D printer used to make Emma’s plastic arms is a commercial model, but even home 3D printers can make useful, life-changing objects.