Sound sieve lets you choose what to levitate - tech - 20 June 2014 - New Scientist

Sound sieve lets you choose what to levitate - tech - 20 June 2014 - New Scientist: The team etched a thin brass plate with rectangular strips and suspended it in a tank of water. Ultrasound blasted from above sends acoustic waves through the water that cause the plate to resonate with the bottom of the tank. The resulting sound pressure lifts objects placed below the plate according to size and density.

The team sorted small glass beads from larger ones and pulled glass beads away from tin beads of the same size...

Unbelievable Display Technology Uses Levitating Particles as Pixels

Unbelievable Display Technology Uses Levitating Particles as Pixels: Researchers actually figured out how to levitate objects using nothing but sound years ago, but to date it's really only been with single particles. This new research, from Yoichi Ochiai, Takayuki Hoshi, and Jun Rekimoto, presented at the annual Siggraph conference, involves hundreds of tiny specks, all strategically arranged in real-time to form images, and even moving animations.

Whoa: Watch Scientists Use Sound Waves to Make Things Levitate | Wired Design | Wired.com

Whoa: Watch Scientists Use Sound Waves to Make Things Levitate | Wired Design | Wired.com: ...scientists have been experimenting with acoustic levitation for decades, using sound waves to suspend materials in mid-air. What’s new here, though, is the ability to move those materials in three dimensions.

That’s made possible by the unique arrangement of the speakers themselves. Where former setups bounced sound waves off a solid plate, the Tokyo researchers instead use four panels of speakers, all facing each other. These walls combine to create an “ultrasonic focal point,” which can be moved—along with the object trapped in it—by adjusting the output from each speaker array.

Fastest rotating man-made object created

Fastest rotating man-made object created: To do this they manufactured a microscopic sphere of calcium carbonate only 4 millionths of a metre in diameter. The team then used the miniscule forces of laser light to hold the sphere with the radiation pressure of light...
They exploited the property of polarisation of the laser light that changed as the light passed through the levitating sphere, exerting a small twist or torque.
Placing the sphere in vacuum largely removed the drag (friction) due to any gas environment, allowing the team to achieve the very high rotation rates...

"I am intrigued with the prospect of extending this to multiple trapped particles and rotating systems. We may even be able to shed light on the area of quantum friction – that is – does quantum mechanics put the brakes on the motion or spinning particle even though we are in a near perfect vacuum with no other apparent sources of friction?"

Magically Levitating Balls Could Be the Future of Computer Interfaces

Magically Levitating Balls Could Be the Future of Computer Interfaces: The system utilizes a moving stack of powerful, computer controlled magnets to levitate a steel sphere as well as an optical tracking system and a projector.

Both the user and the computer can communicate by moving a steel ball within a three-dimensional space. The system will track the ball as the user moves it within the space—essentially programming a flight path—and then "play back" ball's exact trajectory indefinitely by manipulating the intensity of the magnets' repulsion. The projecter is used to display images onto the the floating sphere.

Superstuff: When quantum goes big

Superstuff: When quantum goes big: Imagine you have two identical particles, and you swap their positions. The physical system looks exactly the same, and responds to an experiment exactly as before. However, quantum theory records the swap by multiplying their quantum state by a "phase factor". Switching the particles again brings in the phase factor a second time, but the particles are in their original position and so everything returns to its original state. "Since switching the particles twice brings you back to where you were, multiplying by this phase twice must do nothing at all," says John Baez at the Centre for Quantum Technologies in Singapore. This means that squaring the phase must give 1, which in turn means that the phase itself can be equal to 1 or -1.

Blog - Bio-Assembling in 3D with Magnetic Levitation

Blog - Bio-Assembling in 3D with Magnetic Levitation: The secret ingredient is a proprietary mix of nanoparticles the company calls Nanoshuttle. The addition of these particles to a dish of living cells allows them to move in response to magnetic fields that can be varied in three dimensions and across time.

According to an abstract on the work from the just-concluded meeting of the Tissue Engineering International & Regenerative Medicine Society, they've managed to tune this effect until it can create a "BioAssembler" that "leads to rapid formation of levitated 3D cell cultures."

New Scientist TV: Superconducting disc locked in upside-down levitation

New Scientist TV: Superconducting disc locked in upside-down levitation: Almog's disc can be locked in place thanks to tiny gaps in the ultra-thin superconducting coating that allow some of the magnetic fields to seep in. Since the superconductor hates magnetic fields, it traps them in weak areas. So the tiny spaces act as pins, holding up the disc in space.

"We have achieved what was thought to be impossible up until today: growing high quality superconducting layers on sapphire wafers," says Almog. "Since the superconductor is of the highest quality, it allows a micron thick layer to be locked in space with enough power."

'Flying carpet': Princeton team's plastic sheet can hover above ground (w/ video)

'Flying carpet': Princeton team's plastic sheet can hover above ground (w/ video): "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," wrote the three authors, Noah Jafferis, Howard Stone, and James Sturm. “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.”