Foam earphones fit snugly, but-ew-they attract ear gunk. Shure made the covers of these high-end buds washable by flowing foam into a mold that forms a nonporous finish on the outside. Shure SE530 $450;shure.com
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.