How That Lexus Hoverboard Actually Works

This week, Lexus debuted a teaser video of what looks like a hoverboard. Well, it's real. And here's how it works.
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Lexus

This week, Lexus introduced a short teaser video for SLIDE, a hoverboard that appears to not just live up to our Back to the Future II dreams but, at least stylistically, improve on them. Better yet, it's more science than science fiction. Here's how it works---and why you won't find one at Toys'R'Us any time soon.

Let's start with that teaser video, a scant 37 seconds of hoverboard hype that almost prompts more skepticism than excitement. A bamboo and carbon fiber skateboard, emitting wisps of smoke, levitates an inch or two off of what appears to be a concrete surface. A foot approaches as if to mount and ride—and then nothing. We cut away.

That's not a lot to put one's faith in. We're barely a year past the most recent convincing hoverboard hoax---a Funny or Die promotion, it turned out---and are halfway through the year in which BTTFII took place, a ripe time for attention-grabbing tie-ins.

Even the information Lexus did provide at the time didn't jibe with what the teaser shows. According to the company's briefly stated promotional materials, the device employs "magnetic levitation" to achieve (and maintain) lift-off, which would be well and good if it weren't for where it was levitating.

"It's a tease, right? It gives you the impression that this thing is floating on top of concrete," says Mike Norman, Director of the Materials Science Division at Argonne National Lab. "Which it's not."

Fortunately, the bad news stops there. Surface trickery aside---there are probably magnets or steel mixed in or just underneath that concrete---the Lexus hoverboard really does live up to its name.

How It Works

Magnets. That's the short version. The long version means steeling yourself for a light dose of physics.

According to Lexus, its hoverboard relies on superconductors and magnets, which combine to repel the force of gravity and lift an object---like, say, a fancy skateboard and its rider---above the ground.

That may sound familiar to anyone who recalls the Hendo hoverboard, which debuted as a Kickstarter last fall. You can read about the physics behind the Hendo in great depth here, but the key difference between it and the Lexus project is that Lexus opted for a superconductor---which creates a different kind of magnetic field---instead of a plain ol' conductor.

"With a superconductor you don't need to have an oscillating magnetic field [like Hendo's]," explains Eric Palm, Deputy Laboratory Director at FSU's National High Magnetic Field Laboratory. "Instead you have something called the Meissner effect, which essentially says that when you take a magnetic field near the superconductor, it induces current in that superconductor, and creates essentially an image magnetic field on the other side of the superconductor. You create current, but since it's a superconductor, the currents don't die away. So you don't need oscillating magnetic fields. You can have a magnet that levitates above a superconductor or vice versa, a superconductor that levitates above a magnet."

If that all sounds a little technical, try to picture a maglev train, which relies on similar principles to achieve speeds of, in the case of Shanghai's Transrapid, over 300mph. Or better yet, watch this video, recommended by Norman, of a superconductor locked in a magnetic field:

As for the wisps of smoke you see rising from the sides of the Lexus board? That's not just for effect (although as effects go, it ain't bad). That's liquid nitrogen, cooling the superconductors below their transition temperature—the temp at which it becomes superconducting. Just how cold are we talking? -321 degrees Farenheit, says Palm, who also cautions that it's not quite as extreme as it sounds. "That sounds very cold," Palm explains, "but liquid nitrogen is actually a byproduct of the steel industry, so it's pretty inexpensive." It's the same principle as the dry ice you played with in AP Chemistry, just around three times as cold.

When the liquid nitrogen runs out, the superconductors warm up and the hoverboard stops, well, hovering, until you top it off again.

Here's one last barebones, layman's definition that might help, compliments of Norman. "There's interaction between the superconductor and the magnet that repels the force of gravity and allows the thing to levitate," Norman says. That's why it can't be pure concrete in the video; there has to be something magnetic there as well. When you apply the same principles to a human-bearing board, "it really is like you're floating."

He would know; while he hasn't ridden the Lexus hoverboard, he's spent time on a similar contraption in a lab. As it turns out, for all the anguish and anticipation around making hoverboards real, they have existed for some time. And they're not all that hard to make.

And yet! A brief teaser of the Lexus version has racked up well over three million views in just two days, a response that surprised few more than Lexus itself.

A Good Problem to Have

"Back to the Future messed my whole generation up." That's Lexus spokesperson Maurice Durand's take. "The world so desperately wants someone to mass produce a hoverboard."

Sorry to disappoint, but that someone is probably not Lexus. All SLIDE has ever been, says Durand, is part of a marketing campaign for an as yet unannounced car. (And no, the car won't float either). In truth, Lexus didn't even build the hoverboard itself; it partnered with outside agencies to create what turned out to be a surprise viral sensation.

"Let's be frank, it's not novel," says Durand. "There are other hoverboards. To a degree, we weren't expecting [the reaction]."

But while it's true that the Lexus hoverboard doesn't represent any scientific breakthroughs, it's perhaps not a total shock that it captured so many hearts and views. There's the use of not-quite-concrete, for one, which gives the false, aspirational impression that you can take this hoverboard with you anywhere you go. More important than that, though, might be that where previous working hoverboards have looked like something out of a poorly sweded version of Tron, the Lexus take looks downright luxury-grade.

That makes sense, says Durand, not only because of who made it but what it was made for. "I don't know how many hoverboards were built to feature in a global ad campaign," Durand explains, noting that SLIDE takes several design cues, like bamboo finish and carbon fiber touches, from the Lexus automobiles it's helping promote. In short, it may be the first functional hoverboard whose form lives up to---or even outshines---its function.

As for when we'll actually see SLIDE in action, maybe just in the full version of the ad? That could be anywhere from several more weeks to a couple of months. The intense interest has seemingly put Lexus in the slightly disjointed position of both basking in the viral glow (it's by far the most popular entry in this particular marketing series) and dampening expectations (no, they're not selling this, but can we interest you in a car?).

"Will they remember the hoverboard more than the car that's going to be in [the ad]? That's a distinct possibility based on the reaction so far," says Durand, who doesn't seem especially concerned. The only thing he really needs people to remember, after all, is Lexus.

Don't expect to see SLIDE anywhere else any time soon. A maglev hoverboard won't work on any appreciable scale until our streets and sidewalks are paved with magnets, and even then they're a wildly impractical mode of transportation. Despite that, Durand offers up just a small morsel of hope for your hoverboard future.

"I would never say never that it wouldn't be something we'd have for consumer use," he says, with seemingly total sincerity. Sure, it would take a total overhaul of our current infrastructure to even approach plausibility. But is that any more crazy than skateboards that fly?

Well, yes, OK, probably. That doesn't mean we can't dream of it, though---a levitation-filled future hovering just inches away from gravity's reach.