Gizmodo: sound waves

Sound Wave Harvesting Justifies Your Annoyingly Loud Phone Voice

Wilson Rothman — Wed, 03 Dec 2008 22:30:00 EST

The surge of systems devised to re-capture bodily output continues, this time with a nano-piezo technology that could use sound waves to charge cellphones. But how long must you talk before you can... talk? Science Daily reports that Tahir Cagin, a professor in the chemical engineering department at Texas A&M, has merged the really old science of piezoelectrics with the very new science of nanotechnology to discover that a technique for harvesting energy actually gets way more efficient at the nano level. Specifically, when a piezoelectric film used to convert vibrations into energy is reduced to around 21 nanometers in thickness, it's suddenly twice as good at converting the energy. There's not a lot of detail on the uses for this technology just yet, and—like other vibration-power systems—the earliest uses would probably be in very low energy applications such as sensors. But the article does suggest this could have "potentially profound effects for low-powered electronic devices such as cell phones, laptops, personal communicators and a host of other computer-related devices," though I wonder if that wasn't just thrown in to make people like me excited about it. It worked. I am. [Science Daily via TreeHugger]

Sound Sewing Machine Concept Shows You the Music

Erica Ho — Fri, 14 Nov 2008 21:30:00 EST

This concept of a sewing machine was created by SOUNDS.BUTTER, a design group interested in physically representing sound waves. They sought to represent it tactically instead of digitally where sound is oft seen in sound and music editing. The sewing machine was chosen because of its association with industriousness and physicality. While it is a very unique concept, I'd be curious to see exactly what Metallica would look like under this sewing machine—would it actually turn into a picture of sex and drugs? [SOUNDS.BUTTER via Design Boom]

Sound Wave-Driven Liquid Lenses Good For Lightweight Future Phones, UAVs

Kit Eaton — Tue, 23 Sep 2008 06:12:28 EDT

Scientists at Rensselaer Polytechnic Institute have come up with this freaky adaptive liquid-lens that can capture 250 in-focus images per second. It's essentially droplets of water in a pair, trapped in chamber and driven by a high-frequency sound wave to oscillate.

As the drops wiggle back and forth, surface tension changes the droplet's shapes, and thus the light-focusing performance each has: images are then captured by a standard sensor placed at the focal point behind the droplet assembly. Bespoke imaging software then coordinates with the in-focus moments and records the images, disposing of the out-of-focus ones.

Basically the system makes photos that're "almost always in focus – no matter how close or far away it is from an object" according to the project leader. And since the tech is cheap and relatively simple to implement, the science team thinks it's the sort of thing you'll see in cellphones in the future, and possibly in UAVs and other gadgets with imaging requirements. [Physorg]

Sound Visualization Trick Works Like an Audio Spirograph

Charlie White — Thu, 25 Oct 2007 12:04:18 EDT

There's not a whole lot of explanation attached to this video clip, but this is either white sand, powder or flour (or maybe it's a zillion dollars' worth of coke) showing the shape of sound. The sound waves make the tiny particles organize themselves into symmetrical patterns. We found ourselves mesmerized by the various shapes that pop up and change with certain frequencies. Hey, it's like a crude audio-to-visual converter. Now if someone could just make one of these things that's not so obnoxiously noisy, it might make a great coffee table decoration under glass. That said, you might want to turn your sound down a bit before you play this clip. [Metacafe]