The 1989 classic Back to the Future Part II predicted a lot many futuristic technologies, of which Marty McFly’s Mattel Hoverboard was the most fantasized one (to me at least!). Toyota’s luxury car brand Lexus just went ahead and successfully replicated the technology in Hoverboard, which received mixed reviews from professional riders and skateboarders. This may not come out as a surprise, as the hoverboard banks on superconductors and magnets to defy gravity and lift the board above ground. The steam let off of the sides is a result of liquid nitrogen cooling the superconductors (composed of yttrium, barium, copper, and oxygen) to -321 degrees Fahrenheit (or -180 degrees Celsius), a temperature where superconductors normally function.
The hoverboard’s stuffed with ceramic tiles (superconductors), and in order to gain levitation, the board must be resting on a magnetic track, while several wooden planks placed under the board shall determine its levitation height (more wood = more height, the maximum height being 4cm). Once the board hits the required critical temperature of -321 degrees Fahrenheit, the superconductors engage with the magnets by flux pinning, and there’s your steaming hoverboard.
The hoverboard hovers for approximately 20 minutes, depending on the weight of the rider and on the temperature. Once the board evaporates its liquid nitrogen, the superconductivity is lost and needs to be refilled.
Lexus has even given out a bonus video explaining the physics behind it all-