A Hovering Vacuum That Protects Your Floors And Looks Good Doing It

You can pretend a broom is a useful way to clean wood and tile floors, but in reality, it just moves the dirt elsewhere. A vacuum is still your best option-but even better than that is a vacuum that floats across scratch-prone hard floors like a hovercraft. Say hello to the aiRider.

In order to create suction, a vacuum has to move a lot of air, which is why there's always a hot blast coming out of some part of a vacuum. With the aiRider, it's directed straight down into a shallow chamber beneath the canister that causes it to effortlessly float on hard floors without scratching them to bits. It's probably less effective at floating on carpets, but no less easy to drag around.

A One-String Pen-Sized Guitar That Almost Plays Like the Real Thing

They're not as awkward to transport as a piano or a cello, but guitars are far from being the easiest instrument to travel with. And if air guitar never really satisfies your desire to play while away from your instrument, this pen-sized single-string playable guitar might be a better traveling companion.

Currently trying to raise $35,000 on Kickstarter, the FretPen is to your guitar what the Game Boy was to your home gaming console. A compact portable alternative that can surprisingly be played just like a full-sized guitar.

The fretboard-made from real maple wood-can detect multiple finger placements, while the limited selection of notes you can play can be adjusted using a four-way controller on the bottom part of the tiny guitar. There doesn't appear to be any strumming required to play it-you just tap the frets-but the single guitar string is still a nice touch.

The actual sounds produced by the FretPen don't come from the pen itself. With the guitar body attached to the bottom, it connects to an accompanying smartphone app over Bluetooth which is responsible for turning the player's finger taps into actual guitar sounds-either acoustic or electric. And the sounds can be tweaked, with reverb and other effects, all within the app. It won't sound like a giant Fender speaker on stage, but the sound produced by your smartphone's speaker should suitably match the diminutive FretPen.

The first 50 people to donate to the FretPen's crowdsourcing initiative can pre-order one for just $100. But if you'd like to hold off until it's officially gone into production and smoothed out any bumps along the way you'll probably be able to snag one for closer to $150. And if that seems expensive for an incredibly tiny guitar, don't forget, as its namesake implies, the FretPen can also be used as a writing instrument for those times when you need to jot down a memorable riff you just came up with.

Sony a6000 Review: A Solid Mirrorless Camera That's a Small Step Up

Pretty much all mirrorless cameras-Fujifilm X, Samsung NX, to name a couple-with APS-C size sensors can take a damn fine picture these days. The a6000 does its best to stand out with a pinch of style and updated tech, but it's still largely the same as the camera it's replacing, 2012's NEX-6.

What Is It?

Sony's NEX moniker may be dead, but the cameras themselves are still very much alive as the Alpha (a) series. The a6000 is a mid-range mirrorless camera with a 24 megapixel APS-C size sensor, taking Sony's E-mount lenses. It costs $650 for the body only, and $800 with a 16-50mm f/3.5-5.6 kit lens.

Why Does It Matter?

It's the first camera in Sony's revamped Alpha line to aim higher than entry-level. It replaces not only the NEX-6 but the arguably groundbreaking NEX-7, introduced way back in 2011. Not to mention that Sony's innovative A7 and A7r full-frame cameras have also upped the anticipation of whatever comes next.

Design

While largely reflecting the overall shape of the NEX series, the a6000 has adopted more of the clean, angular lines of the a7 and a7r. That's a good thing, because it distinguishes Sony as one of the only mirrorless camera makers with a great-looking design that's not based on retro styling. Instead, a modern approach is taken while not overdoing it with unseemly curves and ornamentation.

The camera is very rectangular, with a completely flat top that is very distinctive, though maybe not the most functional design in the world, as it makes the upper dials feel a bit buried. What is function is its big shapely grip-the best grip on any mirrorless camera, in my opinion. The details remain true to the form of past NEX cameras, the feel of the buttons, the LCD, the popup flash. If it aint broke, don't fix it.

Using It

The a6000 takes great, high quality pictures. But if you were hoping for a major step up over last year's generation, you might be disappointed. The new 24 megapixel sensor is an increase from 16 megapixels on the NEX-6, but the quality of the larger images is still the same when looking at RAW files. Low light capability is also the same. In fact, we compared the a6000 with the ancient NEX-C3 in low light and saw no tangible difference.

That doesn't mean the a6000 is a bad camera; it's still near the top when it comes to APS-C image quality, able to hold its own with Fujifilm, Canon, or Nikon. But any reports of this camera significantly outshining its predecessors are overblown or just plain wishful thinking.

Good Points 

That a6000 has a sleek, modern design, with a solid set of controls and a big, comfortable grip. It produces beautiful images and decent video, with fast AF and response time. Controls are logically laid out, and provide a solid set of customizable buttons. The EVF is also great, and sets it apart from other mirrorless options at $650.

Bad Points

Despite the bump in resolution, image quality remains largely stagnant from previous generations. Some of the buttons could benefit from some tactile differentiation. No microphone jack puts the camera at a huge disadvantage for video shooters. The E-mount ecosystem is still lacking in autofocus lens options, particularly fast prime lenses.

Should You Buy It

For $650, body-only, the a6000 has strong value for the image quality and features you get. It's not a huge upgrade from the NEX-6, unless you really care about giant-sized images or having the latest, speediest autofocus. So keep your eye out for lower prices on that older version.

Around this price point, your mirrorless alternatives are the Olympus EM-10 at $700, which is smaller, with killer in-body stabilization and amazing lenses, but inferior resolution and slightly lower image quality in low light. The same is true for the Panasonic GX7, which, for $800, will get you superior video quality to boot. Fujifilm's X-E2 provides the same features and similar image quality, but is much more expensive at $900 body-only.

It seems like Sony is still in need of a killer feature or two to really set its APS-C mirrorless cameras apart from the competition, but until that happens a6000 represents a solid all-around shooter at a great price. And that'll be even more true if it just kicks its lens production into high gear.

The Cool Promise of Machines That Run on Body Heat

The human body at rest radiates 100 watts of heat-heat that does nothing other than make crowded rooms stuffy. But body heat can be converted to electricity, and new technology is always improving the process. With the rise of wearables, the body heat-powered device becomes an ever more tantalizing promise.

In theory, 100 watts would be more than enough to power your lightbulbs or your iPhone. In practice, the current technology doesn't convert heat to electricity that efficiently, and you don't really want to be swaddled head-to-toe in thermoelectric fabric. But we can certainly sweat our way to heat-powered watches and flashlights. In fact, these already exist.

How to Turn Heat Into Electricity

A quick primer on how heat-to-electricity conversion all works. It's all because of a physical phenomenon aptly called the thermoelectric effect. Think USB-charged drink coolers, which use the same effect but in the opposite direction.

Thermoelectric material is made out of a doped semiconductor, such as bismuth telluride or lead telluride. When there's a temperature difference between two sides of the material, charged particles begin to move from the hot to the cold side. This movement generates an electric current-voila, electricity. Much of the world's electricity is in fact converted by this thermoelectric material.

But putting power plant technology on the human body has its challenges. For one, the thermoelectric effect only works when there's a temperature gradient, which is fine when you have superheated steam. But when the human body tops out at 98.6 degrees Fahrenheit and it's a sweltering summer day, then good luck. On a cold day, current thermoelectric materials can generate a few milliwatts of power from body heat.

The Body Heat-Powered Devices of Past and Present

The first commercial body-heated powered gadget actually dates back to 1998, when Seiko sold 500 of its limited edition Seiko Thermic watches. It sold out in just a few months. Wayne Lee, a watch enthusiast based in Malaysia, called the Thermic a "'must-have' to those watch collectors whom possessed a deep passion for marvel technology."

While Lee enthuses about the Thermic in his in-depth review, living in Malaysia quickly teaches him the limits of the technology.

However, to be frank, I would not recommend anyone from the tropics who work outdoor most of the time to purchase the watch. This afternoon when I got inside my "oven hot" car which had been exposed to the sun for several hours (I could not find a parking space under the shade this morning), the second hand stopped ticking. I was panic and quickly get back home to check the manual.

Lee, however, says he spends over 10 hours a day working in an air-conditioned room as a professor, so it's not a problem for him.

Researchers who work with medical devices are, understandably, also very interested in harnessing body heat. The Belgian researchers Vladimir Leonov and Ruud J.M. Vullers created first a blood oxygen sensor and then a brain EEG device. The EEG device, however, was more power hungry, and volunteers complained that the heat-transferring thermoelectric material was uncomfortably cold against the skin.

While the current technology isn't perfect, it's not hard to use. Last year, a tenth grader named Ann Makosinski created a body heat-powered LED flashlight, which made her a finalist for the Google Science Fair. She was able to make her flashlight with Peltier tiles, small devices that convert heat to electricity per the thermoelectric effect. They're readily available for a few bucks a pop.

You can also check out this DIY ring made with Pelltier tiles that lights up with body heat.

New Technology, New Possibilities

While that light-up ring has DIY cred, it's kind of clunky and certainly not the most practical of body heat-powered devices. Sure, thermoelectric materials of the future need to be more efficient, converting more power and working at higher temperatures, but they also need to be morewearable.Recently, researchers in Korea have found a way to embed thermoelectric material in flexible glass fabric, rather than the usually clunky aluminum or ceramic. The thin flexible glass can flex with the curves of the human body, like in this wristband being tested above.

Power Felt, for another example, is a wearable fabric developed by researchers at Wake Forest University. It ditches the semiconductors made of metal for carbon nanotubes woven into plastic fibers. Wrapped around pipes, roof tiles, or your sweaty body, it can make use of otherwise wasted heat.

The amount of power from the Power Felt is currently tiny-140 nanowatts or "a millionth of the power your iPhone uses when it's idle"-it would be especially promising if improved. Clothes-already an interface between our warm bodies and the cool environment-are perfectly positioned to turn temperature differences into power. The coolest jacket could be the one that charges your phone.

A GPS Surfer's Watch That Keeps Track of Every Wave Conquered

Metrics and data analysis are a big part of any sport. Every athlete is always pushing themselves to be faster, stronger, and better, and now even surfers have a way to keep track of their performance when they hit the surf (other than knowing they survived) with the Search GPS watchfrom Rip Curl.

The waterproof wearable uses built-in GPS hardware and other motion sensors to track how many waves you rode, the top speed you hit on your board, and of course where exactly your surfing adventures took you.

That data can all be synced back to an accompanying smartphone app that lets you map the course you took so that you can determine where your best surfing moments took place, and remember where the best waves were. Pricing and availability for the watch haven't been revealed just yet, but with a monochrome LCD display and buttons instead of a touchscreen, it might actually be affordable for less-than-employed beach bums.