HONORABLE MENTION: Malaria kills hundreds of thousands of people every year—most of whom live in sub-Saharan Africa—but getting a diagnosis usually requires examining a blood test under a microscope. Uganda-based Matibabu is trying to change that with a new device that, once placed on a patient’s finger, uses light sensors to detect the malaria-causing parasite within two minutes. It needs more testing before a full rollout, but early results have been promising.