TWIE 143: Sonar Cloaking

This Week in Engineering - Kepler successor approved; bladeless wind turbines; sonar cloaking; activist safety bracelet; brain wave busy signal; and quadrotor fishes like an eagle.

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Kepler successor approved
At the time of this writing, the Kepler space telescope has found 2740 exoplanet candidates by measuring the dimming from transits in front of stars. And while the Kepler¦s mission has been extended to 2016, it still can only survey 0.28% of the sky at any time. Now, NASA has announced TESS, the Transiting Exoplanet Survey Satellite, a $200 million mission to take over hunting for exoplanets after Kepler retires. TESS will survey the entire sky, focusing especially on planets comparable in size to Earth, scheduled to launch in 2017.

Bladeless wind turbines
Dutch architecture firm Mecanoo, teaming up with researchers from Delft Technical University, are working to develop EWICON, or electrostatic wind energy converter -- a wind turbine that generates power without rotating blades. Traditional turbines use wind to move turbine blades, and convert that kinetic energy into electricity, but EWICON uses wind to move charged particles through an electric field to directly generate a voltage, without all the moving parts that require maintenance. To date only a few small prototypes have been developed, and research is ongoing. I say, there¦s no reason to move blades when all you want is electricity... but I still want to build my wind-powered Cuisinart!

Sonar cloaking
Electrical engineer Jose Sanches-Dehesa and colleages at the Polytechnic Institute of Valencia in Spain have 3D-printed a cover with a specific shape that makes an object invisible to sonar. The device was made of sixty rings of various sizes, designed using computer algorithms so that sound waves would interfere with each other as they bounced off. The cloaking only works at a specific frequency of 8.55 kHz, which is an audible high pitch to human ears. I say a sonar cloaking device is the perfect gift for anyone who¦s afraid of being murdered by dolphins or bats. Like Vince.

Activist safety bracelet
Civil Rights Defenders, an organization based in Stockholm, Sweden, is distributing a new bracelet to activists and aid workers in dangerous parts of the world who may face danger of being abducted. When activated by the wearer, or when forcibly removed, the GPS-equipped bracelet sends the potential victim¦s identity and location to headquarters and to other workers, and also posts social media messages. The device was inspired by the story of Natalia Estemirova, who was abducted and killed while documenting human rights abuses in Chechnya. Civil Rights Defenders hopes to distribute fifty-five of the bracelets over the next year and a half.

Brain wave busy signal
The Necomimi Cat Ears are a cute toy that uses electroencephalography to detect when your brain is intensely focused, and wiggles the toy ears in response. Now, the Good Times Project has removed the toy ears, and connected the EEG to a smartphone via Bluetooth. If the wearer receives an incoming call but the device measures intense mental focus, then the call goes straight to voicemail. The Good Times Project is a fun demonstration, but is not expected to go to retail. I love it, but I think it should also read my mind when I don¦t want to talk to you because I hate you so much. You know who you are.

Quadrotor fishes like an eagle
Scientists from the University of Pennsylvania have equipped a quadrotor drone with a forward-pointing claw, so it can swoop down and grab a target in the same way an eagle grabs a fish. By studying footage of actual eagles, the team realized that the claw had to sweep backward to pick up its prey, to eliminate the need to slow down. The project required significant software work for stabilization in order to fly smoothly after picking up the comparatively heavy payload. I love robot eagles, but show me the robot that can swim and catch fish like a penguin. Y