Zeussy writes: While looking around thingiverse for something to 3D print. I found this awesome public domain prosthetic hand designed for a 5 year old child called Liam, who was born without any fingers on his right hand. The design simply using parts either 3D printer and brought from your hardware store. It is body powered via cables and bungees, see it in action here. They are currently running a fundly Fundraiser, give them your support!
We warn the reader in advance that the proof presented here depends on a
clever but highly unmotivated trick.
-- Howard Anton, "Elementary Linear Algebra"