An Indian inventor has come up with a new way to combat air pollution: Turn it into ink. Anirudh Sharma is from the city of Delhi, where air pollution is a serious problem. Inspired to help address it, he and the company he co-founded developed a device to capture exhaust from engines and smokestacks and a way to turn that exhaust into ink. The ink is now available in the form of Air-Ink markers. Sharma hopes it will one day be used in printer cartridges and for printing books and more.