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Science

Magic carpet ride could be one step closer after levitation breakthrough by Hong Kong scientists

Chinese University researchers say device is far less costly than existing maglev systems

PUBLISHED : Monday, 09 October, 2017, 9:34pm
UPDATED : Tuesday, 10 October, 2017, 6:08pm

Ever wondered if the magic carpet from One Thousand and One Nights could become a reality?

Researchers at the Chinese University of Hong Kong may be getting close, as they have developed a self-levitating device that floats and moves on almost any flat surface.

While the current prototype can only carry light objects such as a smartphone, engineers hope the innovation can eventually be used to build hoverboards or even levitating trains.

Unveiling the results after 18 months of research and tests, the Department of Mechanical and Automation Engineering at Chinese University showcased the capabilities of a modified actuator, a mechanical device that converts energy into motion.

Using what they call “near-field acoustic levitation principles”, the device transforms electric currents into ultrasonic vibrations of over 20,000 Hz.

This creates a 0.1 millimetre thin film of air – roughly the size of a strand of hair – wedged between the object and the ground, effectively making the device levitate.

During his demonstration, Assistant Professor Guo Ping , who led the research, was able to move a metal weight connected to electricity over a smooth plastic surface, without applying any external force.

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The actuator’s two-dimensional movement is controlled by adjusting the vibration frequency.

“[The surface] can be metal, glass, or even acrylic – there are no restrictions on the surface material, but it has to be flat and smooth,” Guo said.

Another advantage of the system is its low cost. The prototype model can be produced for HK$500, less than one-hundredth of the cost for a corresponding magnetic levitation – maglev – devices.

At present the device can carry objects of up to 200g, or around the weight of an Apple iPhone 8 Plus.

“With further development, we hope the capacity can be increased to 5-10kg in two years’ time, and 70kg in five years,” Guo said.

Apart from hoverboards and robots, he believes the technology can eventually be used to manufacture non-contact transport systems, such as levitating trains.

But this requires another breakthrough – at the moment the actuator can only move 2.5 metres per second, or 9km per hour.

“Of course we cannot compare it to maglev technology now. As you can see, [the prototype] is still moving quite slowly,” he conceded.

He also rejected comparisons to the Hyperloop, a concept train system which runs through a vacuum tube with speeds of up to 1,200km per hour.