he’s created a rather neat 3D-printed coffee grinder. Sadly the creation of a steel burr and ring was beyond his 3D-printing capabilities so those parts come from a commercial grinder ...

So, should one of the 3D-printed items outlive its usefulness ... And when you don't want it anymore, you can throw it back into a coffee grinder and use the grounds to print again," Rivera said.

It sounds like science fiction. Marvel Labs converts disused waste—including seaweed, coffee grounds, and sawdust—and processes it for use in a 3D printing technique called binder jetting.