While your friends may not be able to sign this cast, it sure looks a huge improvement on the old one. This new 3D-printed alternative kind of looks like a black plastic spider web wrapped around your arm and it uses an ultrasound device to make your broken bone heal faster. Oh, and it also doesn’t get as itchy and smelly as traditional casts. The cast, which was designed by Deniz Karasahin, allows for better ventilation and is slimmer and lighter.