Don't tell Frank Herbert (or the people at Thinx), but he actually came up with a pretty genius pair of menstrual underwear. Only, well, his was outerwear--and it did a lot more than collect blood and endometrial lining. Herbert's invention is, of course, the stillsuit. One of the iconic pieces of tech in his novel Dune--and an iconic piece of sci-fi tech, period--it's an invention born of necessity. Arrakis, where most of the novel takes place, is a desert; to survive, the planet's native Fremen construct form-fitting suits that collect all of their moist excretions--sweat, urine, feces, droplets from exhaled breath--and recycle them into potable water.