Is it possible to build a robotic nose?

Dogs can smell explosives like landmines, and detect medical conditions including seizures, diabetes, and many forms of cancer — with up to 98% accuracy. Inventor Andreas Mershin wants to replicate that — and put a nose in every cell phone. WIRED’s Emily Dreyfuss spoke with Mershin to find out why that’s easier said than done, and to learn what building a robotic nose has taught us about smell.