Manta ray inspires Princeton researcher to create 'magic carpet'
4-inch prototype floats, travels on air currents via 'ripple power.'
Mon, Oct 03, 2011 at 11:49 AM
A Princeton University graduate student has created a real flying carpet, a sheet of plastic that travels through the air in a manner not unlike the way giant manta rays swim through the water.
But don't start thinking of riding a magic carpet to work just yet. The prototype, invented by Noah Jafferis and described in the current issue of Applied Physics Letters, is only four inches across. Made of transparent plastic embedded with threads that conduct electricity, it forms tiny air pockets underneath itself and can propel itself forward at a rate of one centimeter per second.
The tiny sheet of plastic has a fairly limited range so far. "It has to keep close to the ground," Jafferis told the BBC, "because the air is then trapped between the sheet and the ground." But the air pockets that lift it also serve as its source of propulsion, what Jafferis called "ripple power": "As the waves move along the sheet, it basically pumps the air out the back."
This is what Jafferis and his co-authors had to say in the paper's abstract: "We use integrated piezoelectric actuators and sensors to demonstrate the propulsive force produced by controllable transverse traveling waves in a thin plastic sheet suspended in air above a flat surface, thus confirming the physical basis for a 'flying' carpet near a horizontal surface. Experiments are conducted to determine the dependence of the force on the height above the ground and the amplitude of the traveling wave, which qualitatively confirm previous theoretical predictions."
Right now, this isn't a practical device. Jafferis told the BBC that hooking the prototype up to heavy batteries limits the distance it can travel. But he says he is working on a solar-powered version that would afford more freedom. But even that change doesn't generate enough energy to lift a person, at least not at its current size and using existing materials. He says it would take a carpet at least 50 meters across to carry a human passenger.
Jafferis hasn't announced a timeframe for taking his discovery further. It took his team two years to get to this point.
If you can't wait to take a magic carpet ride yourself, check out these 23 seconds of video of the prototype in action:
Also on MNN: