The millions of folks with fond memories of Back to the Future Part II may find that disappointing, but Felton had well-founded reasons for deciding not to pursue the hover tech. Unlike the boards that pervade science fiction, Google’s concept, much like Lexus’ Slide, required a series of magnets to float. The team at Google X couldn’t think of a use case beyond enthusiasts within the “skater crowd,” Felton said.
Google’s prototype presumably relied on superconductors, materials that when sufficiently cooled transmit electricity without resistance. Superconductors suspended in a metallic field are a fairly close approximation of levitating objects, but they aren’t the most practical foundation for a hoverboard. Keeping them in place requires a source of magnetism and constant cooling, usually with liquid nitrogen.
Still, that hasn’t stopped some companies from iterating on the idea. The Hendo hoverboard floats above metal sheets using a downward-facing array of superconductors, but it’s not efficient or cheap — it uses 40 watts of power per 2.2 pounds of weight, around a quarter of the energy use of a helicopter, and costs $10,000.
The technology underlying modern-day hoverboards will undoubtedly improve — Hendo’s already working on a newer version of its product, and an independently constructed, propeller-based machine recently beat the Guinness World Record for farthest distance traveled on a hoverboard — but it’ll probably be a long time before a hoverboard like anything we’ve seen in movies comes to market.