Tag Archives: interesting research

Scientists Build Lasers Out of Sound, Call Them Phasers

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Sound lasers work on a similar principle. For Mahboob and his team’s phaser, a mechanical oscillator jiggles and excites a bunch of phonons, which relax and release their energy back into the device. The confined energy causes the phaser to vibrate at its fundamental frequency but with at a very narrow wavelength. The sound laser produces phonons at 170 kilohertz, far above human hearing range, which peters out around 20 kilohertz. The entire device is etched onto an integrated circuit that’s about 1 cm by 0.5 cm.

via Pew Pew! Scientists Build Lasers Out of Sound, Call Them Phasers | Wired Science | Wired.com.

A New Molten-Salt Reactor Could Halve the Cost of Nuclear Power

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The new reactor design, which so far exists only on paper, produces 20 times as much power for its size as Oak Ridge’s technology. That means relatively small, yet powerful, reactors could be built less expensively in factories and shipped by rail instead of being built on site like conventional ones. Transatomic also modified the original molten-salt design to allow it to run on nuclear waste.

via A New Molten-Salt Reactor Could Halve the Cost of Nuclear Power | MIT Technology Review.

In the event of a power outage, a stopper at the bottom of the reactor melts and the fuel and salt flow into a holding tank, where the fuel spreads out enough for the reactions to stop. The salt then cools and solidifies, encapsulating the radioactive materials. “It’s walk-away safe,” says Dewan, the company’s chief science officer. “If you lose electricity, even if there are no operators on site to pull levers, it will coast to a stop.”

Throwing and catching an inverted pendulum

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Armed with a good theoretical model and knowledge of its strengths and limitations, the researchers set out on a process of engineering the complete system of balancing, throwing, catching, and re-balancing the pendulum. This involved leveraging the theoretic insights on the problem’s key design parameters to adapt the physical system. For example, they equipped both quadrocopters with a 12cm plate that could hold the pendulum while balancing and developed shock absorbers to add at the pendulum’s tips.

via Video: Throwing and catching an inverted pendulum – with quadrocopters | Robohub.

Below is the Youtube video.

More info at the Flying Machine Arena.

The Flying Machine Arena (FMA) is a portable space devoted to autonomous flight. Measuring up to 10 x 10 x 10 meters, it consists of a high-precision motion capture system, a wireless communication network, and custom software executing sophisticated algorithms for estimation and control.

China’s radical new space drive

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It may not sound very much, less than three ounces, but in space a little thrust goes a long way. Boeing’s advanced XIPS thruster, which fires out Xenon ions at high speed, generates less than a quarter as much thrust from twice as much power. It’s used to maintain satellites in position, or move them to a slightly different orbit. Crucially, Xips weights about twenty kilos, more than an equivalent EmDrive, and the propellant for prolonged operation can weigh much more.

via EmDrive: China’s radical new space drive (Wired UK).

Magnetic logic makes for mutable chips

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A research group based at the Korea Institute of Science and Technology (KIST) in Seoul, South Korea, has developed a circuit that may get around these problems. The device, described in a paper published on Nature’s website on 30 January, uses magnetism to control the flow of electrons across a minuscule bridge of the semiconducting material indium antimonide (S. Joo et al. Nature http://dx.doi.org/10.1038/nature11817; 2013). It is “a new and interesting twist on how to implement a logic gate”, says Gian Salis, a physicist at IBM’s Zurich Research Laboratory in Switzerland.

via Magnetic logic makes for mutable chips : Nature News & Comment.

This seems like a revolutionary discovery if it can be manufactured relatively easily.  And then there’s this:

But Johnson notes that magnetism is already catching on in circuit design: some advanced devices are beginning to use a magnetic version of random access memory, a type of memory that has historically been built only with conventional transistors. “I think a shift is already under way,” he says.

How Lytro is Shifting Our Perspective on Photography

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What’s amazing is how quickly the technology is evolving. There’s no second-generation Lytro yet though it’s safe to assume the Mountain View, CA-based company is working on one. But because light field photography is mostly about computation, not optics or electronics, Lytro can make its existing camera more powerful simply by upgrading the software used to process light-field images.

via How Lytro is Shifting Our Perspective on Photography | Xconomy.

Nanostructures Boost Battery Life Fivefold

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Some of the most promising battery chemistries—which, in theory, could store several times more energy than today’s lithium-ion batteries and cost much less—have a fatal flaw. They can’t be recharged very often before they stop working, making them useless for applications such as electric vehicles. Now researchers at Stanford have created novel nanostructures that greatly increase the number of times one of these chemistries can be recharged, even to levels high enough for many commercial applications.

via Nanostructures Boost Battery Life Fivefold | MIT Technology Review.

Stanford Researchers Make Flexible Solar Cells that Stick to Just About Any Surface

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Researchers led by Xiaolin Zheng, a professor of mechanical engineering at Stanford University, demonstrated a way to transfer the active materials of the solar cell from a rigid substrate onto another surface, such as a sheet of paper or plastic, the roof of a car, or the back of a smartphone. As with other solar cells, wires would then be connected to deliver power, but flexible solar cells could be used on curved surfaces, and, because they’re lightweight, they would be easier to install than conventional panels.

via Stanford Researchers Make Flexible Solar Cells that Stick to Just About Any Surface | MIT Technology Review.

Crushed Silicon Could Triple Your Battery Life

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Engineer Sibani Lisa Biswal and research scientist Madhuri Thakur reported in Nature’s Scientific Reports (it has yet to be published online) that by taking porous silicon and crushing it, they were able to dramatically decrease the volume required for anode material. Silicon has long been looked at as an anode material because it holds up to ten times more lithium ions than graphite, which is most commonly used commercially.

via Crushed Silicon Could Triple Your Battery Life | Motherboard.

The result is a new battery design that holds a charge of 1,000 milliamp hours per gram through 600 tested charge cycles of two hours charging, two hours discharging. According to the team, current graphite anodes can only handle 350 mAh/g.

Optical conveyors: A class of active tractor beams

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A tractor beam is a traveling wave that can transport illuminated material along its length back to its source.

via Optical conveyors: A class of active tractor beams.

Abstract.

We experimentally demonstrate a class of tractor beams created by coherently superposing coaxial Bessel beams. These optical conveyors have periodic intensity variations along their axes that act as highly effective optical traps for micrometer-scale objects. Varying the Bessel beams’ relative phase shifts the traps axially thereby selectively transports trapped objects either downstream or upstream along the length of the beam. The same methods used to project a single optical conveyor can project arrays of independent optical conveyors, allowing bi-directional transport in three dimensions.