Powered by Wind: World’s Tiniest Windmills

tiny_windmillWind turbines are one of the fastest growing industries thanks to their ability to provide clean, renewable energy. And while most designs are trending towards larger and larger sizes and power yields, some are looking in the opposite direction. By equipping everyday objects with tiny windmills, we just might find our way towards a future where batteries are unnecessary.

Professor J.C. Chiao and his postdoc Dr. Smitha Rao of the University of Texas at Arlington are two individuals who are making this idea into a reality. Their new MEMS-based nickel alloy windmill is so small that 10 could be mounted on a single grain of rice. Aimed at very-small-scale energy harvesting applications, these windmills could recharge batteries for smartphones, and directly power ultra-low-power electronic devices.

tiny_windmill1These micro-windmills – called horizontal axis wind turbines – have a three-bladed rotor that is 1.8 mm in diameter, 100 microns thick, and are mounted on a tower about 2 mm tall mount. Despite their tiny size, the micro-windmills can endure strong winds, owing to being constructed of a tough nickel alloy rather than silicon, which is typical of most microelectromechanical systems (MEMS), and a smart aerodynamic design.

According to Dr. Rao, the problem with most MEMS designs is that they are too fragile, owing to silicon and silicon oxide’s brittle nature. Nickel alloy, by contrast, is very durable, and the clever design and size of the windmill means that several thousands of them could be applied to a single 200 mm (8 inch) silicon wafer, which in turn makes for very low cost-per-unit prices.

tiny_windmill2The windmills were crafted using origami techniques that allow two-dimensional shapes to be electroplated on a flat plane, then self-assembled into 3D moving mechanical structures. Rao and Chiao created the windmill for a Taiwanese superconductor company called WinMEMS, which developed the fabrication technique. And as Rao stats, they were interested in her work in micro-robotics:

It’s very gratifying to first be noticed by an international company and second to work on something like this where you can see immediately how it might be used. However, I think we’ve only scratched the surface on how these micro-windmills might be used.

Chiao claims that the windmills could perhaps be crafted into panels of thousands, which could then be attached to the sides of buildings to harvest wind energy for lighting, security, or wireless communication. So in addition to wind tunnels, large turbines, and piezoelectric fronds, literally every surface on a building could be turned into a micro-generator.

Powered by the wind indeed! And in the meantime, check out this video from WinMEMS, showcasing one of the micro-windmills in action:


Source: news.cnet.com, gizmag.com

The Future is Here: The Electric Highway!

electric_carCharging electronic vehicles while they on the move is not a new idea. In fact, in Vancouver, BC, the entire public transit system runs on a series of electronic lines that power the buses. And in French cities, the entire tram system runs on a wireless system, one which is six million kilometers in length. In the former case, the buses are kept in contact with power lines overhead, while the latter uses metal bars running underneath.

Applying the same concept, Volvo has designed a new highway system in Sweden that will keep electric cars running on long-distance trips. Led by Mats Alaküla, researchers are looking at these types of “conductive charging,” both where vehicles would stay in continuous contact with the power supply. Both methods are being tested on the new system, which consists of a 400-meter track near Gothenburg.

volvo_highwayBehind the research is the assumption that an electric car’s batteries will not provide the required range for long-distance driving, especially where long-haul trucks are concerned. City driving is one thing, but in order for electric vehicles to expand beyond urban centers, bigger and better methods need to be devised.

Alaküla says the important part of the second system is “the pick-up” – i.e. the connector between the vehicle and the ground. Unlike trams that stay in a fixed position, this line needs to be able to compensate for cars and trucks changing lanes. He describes the set-up as an “industrial robot sitting upside down”, though it more akin to a robotic arm.

volvo_highway1The arm moves a meter each way to compensate for movement within the lane, and retracts when the driver changes lanes, redeploying once they’ve back on the track. As Alaküla describes it:

If you imagine two lanes, the power system would be in the right lane. The pick-up keeps in contact with the supply, until you keep moving sideways. Then, the truck will go to the battery. When you go back, it automatically identifies the track, and reconnects.

And for those who worry that electric tracks are going to make highways unsafe for pedestrians, Alaküla insisted that the system only electrifies sections of the track when vehicles pass at a certain speed. To electrocute yourself, a pedestrian would need to step out in front of a fast-moving vehicle, which would kind of render the whole thing moot!

electric-highwaySo far, trucks have been able to get up to speeds of 80 km/h (50 mph) on the Volvo stretch, and Alaküla expects the work to continue for another year before his team takes the concept to a full road. Eventually, he thinks the concept could be used for anything bigger than a motor-bike – from cars and buses to different types of trucks.

And they not alone in their research efforts. Volvo’s rival Scania are themselves testing technology based on inductive charging where the charge is transferred via an electromagnetic field and does not require physical contact. Between these three methods and other emerging technologies that seek to make highway driving “smart”, the future of long-distant driving is likely to become a much cleaner, more efficient affair.

Source: fastcoexist.com