How To 3-D Print Your Own Invisibility Cloak | Popular Science

How To 3-D Print Your Own Invisibility Cloak | Popular Science: Duke University engineer Yaroslav Urzhumov has designed a plastic disk that makes a small object placed in its hollow center invisible to frequencies from 9.7 to 10.1 GHz (close to the range used by radar speed guns). Holes in the doughnut-shaped cloak can eliminate an object’s shadow and decrease its ability to scatter light. In effect, the cloak guides the microwave beams around the object so they can’t bounce back—rendering it invisible.