Wind 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.
These 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.
The 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:
In their quest to build better, smarter and faster machines, researchers are looking to human biology for inspiration. As has been clear for some time, anthropomorphic robot designs cannot be expected to do the work of a person or replace human rescue workers if they are composed of gears, pullies, and hydraulics. Not only would they be too slow, but they would be prone to breakage.
Because of this, researchers have been working looking to create artificial muscles, synthetics tissues that respond to electrical stimuli, are flexible, and able to carry several times their own weight – just like the real thing. Such muscles will not only give robots the ability to move and perform tasks with the same ambulatory range as a human, they are likely to be far stronger than the flesh and blood variety.
And of late, there have been two key developments on this front which may make this vision come true. The first comes from the US Department of Energy ’s Lawrence Berkeley National Laboratory, where a team of researchers have demonstrated a new type of robotic muscle that is 1,000 times more powerful than that of a human’s, and has the ability to catapult an item 50 times its own weight.
The artificial muscle was constructed using vanadium dioxide, a material known for its ability to rapidly change size and shape. Combined with chromium and fashioned with a silicone substrate, the team formed a V-shaped ribbon which formed a coil when released from the substrate. The coil when heated turned into a micro-catapult with the ability to hurl objects – in this case, a proximity sensor.
Vanadium dioxide boasts several useful qualities for creating miniaturized artificial muscles and motors. An insulator at low temperatures, it abruptly becomes a conductor at 67° Celsius (152.6° F), a quality which makes it an energy efficient option for electronic devices. In addition, the vanadium dioxide crystals undergo a change in their physical form when warmed, contracting along one dimension while expanding along the other two.
Junqiao Wu, the team’s project leader, had this to say about their invention in a press statement:
Using a simple design and inorganic materials, we achieve superior performance in power density and speed over the motors and actuators now used in integrated micro-systems… With its combination of power and multi-functionality, our micro-muscle shows great potential for applications that require a high level of functionality integration in a small space.
In short, the concept is a big improvement over existing gears and motors that are currently employed in electronic systems. However, since it is on the scale of nanometers, it’s not exactly Terminator-compliant. However, it does provide some very interesting possibilities for machines of the future, especially where the functionality of micro-systems are concerned.
Another development with the potential to create robotic muscles comes from Duke University, where a team of engineers have found a possible way to turn graphene into a stretchable, retractable material. For years now, the miracle properties of graphene have made it an attractive option for batteries, circuits, capacitors, and transistors.
However, graphene’s tendency to stick together once crumpled has had a somewhat limiting effect on its applications. But by attacking the material to a stretchy polymer film, the Duke researchers were able to crumple and then unfold the material, resulting in a properties that lend it to a broader range of applications- including artificial muscles.
Before adhering the graphene to the rubber film, the researchers first pre-stretched the film to multiple times its original size. The graphene was then attached and, as the rubber film relaxed, the graphene layer compressed and crumpled, forming a pattern where tiny sections were detached. It was this pattern that allowed the graphene to “unfold” when the rubber layer was stretched out again.
The researchers say that by crumpling and stretching, it is possible to tune the graphene from being opaque to transparent, and different polymer films can result in different properties. These include a “soft” material that acts like an artificial muscle. When electricity is applied, the material expands, and when the electricity is cut off, it contracts; the degree of which depends on the amount of voltage used.
Xuanhe Zhao, an Assistant Professor at the Pratt School of Engineering, explained the implications of this discovery:
New artificial muscles are enabling diverse technologies ranging from robotics and drug delivery to energy harvesting and storage. In particular, they promise to greatly improve the quality of life for millions of disabled people by providing affordable devices such as lightweight prostheses and full-page Braille displays.
Currently, artificial muscles in robots are mostly of the pneumatic variety, relying on pressurized air to function. However, few robots use them because they can’t be controlled as precisely as electric motors. It’s possible then, that future robots may use this new rubberized graphene and other carbon-based alternatives as a kind of muscle tissue that would more closely replicate their biological counterparts.
This would not only would this be a boon for robotics, but (as Zhao notes) for amputees and prosthetics as well. Already, bionic devices are restoring ability and even sensation to accident victims, veterans and people who suffer from physical disabilities. By incorporating carbon-based, piezoelectric muscles, these prosthetics could function just like the real thing, but with greater strength and carrying capacity.
And of course, there is the potential for cybernetic enhancement, at least in the long-term. As soon as such technology becomes commercially available, even affordable, people will have the option of swapping out their regular flesh and blood muscles for something a little more “sophisticated” and high-performance. So in addition to killer robots, we might want to keep an eye out for deranged cyborg people!
And be sure to check out this video from the Berkley Lab showing the vanadium dioxide muscle in action:
Big public events are often used to showcase new technology: the Consumer Electronics Show in Las Vegas, the Bett Show in London, and now the Glastonbury outdoor festival in England, where early last the mobile phone company Vodafone chose to showcase a new line: the Power Shorts, an item of clothing that turns motion and even body heat into electricity.
The shorts were naturally a big hit, and quite appropriate for the venue since they use motion (like dancing), to boost the battery life of your mobile devices. Created with help from scientists at the University of Southampton, the shorts incorporate a Power Pocket that contains foam-like ferroelectret materials with pockets of permanently charged surfaces. When the material gets squashed or deformed through movement, kinetic energy gets produced.
But for those who are looking for a way to charge their gear without exertion, Vodafone is also working on a Recharge Sleeping Bag. This bag apparently harvests body heat via the “Seebeck effect,” a process that produces a voltage from the temperature differences across a thermoelectric module.
These modules are printed on the fabric of the sleeping bag, which supposedly can transform an 8-hour snooze into 11 hours of smartphone battery life. As Stephen Beeby, a professor of electronic systems at the University of Southampton who worked on the innovations explained:
One side of that is cold and the other is hot, and when you get a flow of heat through it you can create a voltage and a current. Voltage and current together equals electrical power.
And this is not the first time that Vodafone chose to unveil something new and innovative that just happens to take advantage of the principles of piezoelectricity during a musical event. For those who attended the Isle of Wight Festival last year, the Vodafone Booster Brolley, a prototype parasol that keeps your phone charged while it keeps you dry might ring a bell.
These are by no means the only examples of kinetic energy devices these days. For example, a piezoelectric rubber material produced by Princeton and Caltech a few years back, is already being considered for shoes and other mobile devices as a means of recharging personal electronics.
And remember Pavegen, the rubber panels that turned runners steps at the finishing line of the Paris Marathon into actual electricity? This technology is already being adapted to provide electricity for a Grammar School in Kent, England, utilizing the thousands of steps students take everyday to keep the lights on.
Such concepts are likely to be powering just about all our devices in the not-too-distant future, at least in part. And beyond personal electronics, piezoelectric motors are also sure to be turning up in buildings and public spaces in the near future. In addition to stairways, hallways, and sidewalks, any surface in the city that moves or is touched on a regular basis could be converted to providing power.
Very clean, and very renewable. People still do a great deal of getting around by foot these days, and if we can convert that motion into energy, so much the better!
As the world’s population continues to grow and climate change becomes a greater and greater problem, urban planners and engineers are forced to come up with increasingly creative solutions. On the one hand, the population is expected to rise to an estimated 8.25 billion people by 2030 and 9.25 by 2050, and they will need places to live. On the other, these people will require energy and basic services, and these must be provided in a way that is clean and sustainable.
One such solution is known as the Strawscaper. The brainchild of designer Rahel Belatchew Lerdel, this building would be able to provide its own electricity using only wind and a series of piezoelectric fronds that rustle in the wind. Thanks to this method, the building would get all the power it needs from wind passing through its exterior, and would therefore not need to be attached to the city grid.
In a press release by Belatchew labs, Rahel claimed that the inspiration “came from fields of wheat swaying in the wind”. He also described the building he envisions as one that would give “the impression of a body that is breathing”. Details as to how it would generate its own electricity were also described:
By using piezoelectric technology, a large number of thin straws can produce electricity merely through small movements generated by the wind. The result is a new kind of wind power plant that opens up possibilities of how buildings can produce energy.
The full plan calls for the completion of the Söder Torn, a building in Stockholm that began construction in 1997 but was forcibly scaled down after its architect, Henning Larsen, lost control of the project. Completing it at this point would involve adding an additional 14 stories, thus bringing it from 26 to 40, and adding the piezoelectric fronds to make it electrically self-sufficient.
Though piezoelectricity has never been used in this way, the concept is well understood and backed by a number of research reports. In addition, Belatchew is not the only one considering it as a possible means of generating clean energy. Over in Masdar City, a planned community in Abu Dhabi, something very similar is being proposed to suit their energy needs.
It’s known as the Windstalk, another means of generating electricity from wind without the needs for turbines. Though wind farms have long been considered an effective means of generating sustainable energy, resident living near large-scale operations have voiced concerns about the aesthetics and low-frequency vibrations they claim are generated by them. Thus, the concept of the Windstalk, created by New York design firm Atelier DNA.
The concept consists of 1,203 carbon fiber reinforced resin poles which stand 55 meters (180 feet) high and are anchored to the ground in concrete bases. The poles measure 30cm (12 in.) in diameter at the base and taper up to a diameter of 5cm (2 in.) at the top. Each pole is packed with piezoelectric ceramic discs, between which are electrodes that are connected by cables that run the length of each pole.
Thus, instead of relying on turbines to move magnets and create electrical current, each pole merely sways in the wind, compressing the stack of piezoelectric discs and generating a current through the electrodes. And just to let people know how much – if any – power the poles are generating, the top 50cm (20 in.) of each pole is fitted with an LED lamp that glows and dims relative to the amount of electrical power being generated.
As a way to maximize the amount of electricity the Windstalk farm would generate, the concept also places a torque generator within the concrete base of each pole. As the poles sway, fluid is forced through the cylinders of an array of current generating shock absorbers to convert the kinetic energy of the swaying poles into additional electrical energy. But of course, storage is also an issue, since wind power (like solar) is dependent on weather conditions.
Luckily, the designers at Atelier DNA have that covered too. Beneath a field of poles, two large chambers are located, one on top of the other. When the wind is blowing, part of the electricity generated is used to power a set of pumps that moves water from the lower chamber to the upper one. Then, when the wind dies down, the water flows from the upper chamber down to the lower chamber, turning the pumps into generators.
At the moment, the Windstalk concept, much like the Strawscaper, is still in the design phase. However, the design team estimates that the overall electricity output of the concept would be comparable to that of a conventional wind turbine array because, even though a single wind turbine that is limited to the same height as the poles may produce more energy than a single Windstalk, the Windstalks can be packed in much denser arrays.
Though by all accounts, the situation with our environment is likely to get worse before it gets better, it is encouraging to know that the means exist to build a cleaner, more sustainable future. Between now and 2050, when the worst aspects of Climate Change are expected to hit, the implementation of a better and more sustainable means of living is absolutely crucial. Otherwise, the situation will continue to get worse indefinitely, and the prospects of our survival will become bleak indeed!
For decades, solar power has been dogged by two undeniable problems that have prevented it from replacing fossil fuels as our primary means of energy. The first has to do the cost of producing and installing solar cells, which until recently remained punitively. The second has to do with efficiency, in that conventional photovoltaic cells remained inefficient as far as most cost per watt analyses went. But thanks to a series of developments, solar power has been beating the odds on both fronts and coming down in price.
However, to most people, it was unclear exactly how far it had come down in price. And thanks to a story recently published in The Economist, which comes complete with a helpful infographic, we are now able to see firsthand the progress that’s been made. To call it astounding would be an understatement; and for the keen observer, a certain pattern is certainly discernible.
It’s known as the “Swanson Effect” (or Swanson’s Law), a theory that suggests that the cost of the photovoltaic cells needed to generate solar power falls by 20% with each doubling of global manufacturing capacity. Named after Richard Swanson, the founder of the major American solar-cell manufacturer named SunPower, this law is basically an imitation of Moore’s Law, which states that every 18 months or so, the size of transistors (and also their cost) halves.
What this means, in effect, is that in solar-rich areas of the world, solar power can now compete with gas and coal without the need for clean energy subsidies. As it stands, solar energy still accounts for only a quarter of a percent of the planet’s electricity needs. But when you consider that this represents a 86% increase over last year and prices shall continue to drop, you begin to see a very trend in the making.
What this really means is that within a few decades time, alternative energy won’t be so alternative anymore. Alongside such growth made in wind power, tidal harnesses, and piezoelectric bacterias and kinetic energy generators, fossil fuels, natural gas and coal will soon be the “alternatives” to cheap, abundant and renewable energy. Combined with advances being made in carbon capture and electric/hydrogen fuel cell technology, perhaps all will arrive in time to stave off environmental collapse!
Check out the infographic below and let the good news of the “Swanson Effect” inspire you!:
According to the Laws of Thermal Dynamics, there is no such things as perpetual motion. However, engineers at the University of Michigan seemed to have created a device which defies that rule. Not only that, they seem to have overcome one of the pacemakers greatest drawbacks, i.e. the fact that it requires batteries to keep working. Utilizing a process known as piezoelectricity – electricity generated by pressure and/or external force – they have created the world’s first pacemaker which is powered by the beating of one’s heart.
This is an exciting development for obvious reasons: by creating a pacemaker which can utilize the vibrations in the chest cavity to power itself, this device can function indefinitely. As long as the user’s heart keeps beating, the pacemaker will continue to assist the heart in maintaining its rhythm. Hence the concept of perpetual motion, where feedback is used to keep things going for an infinite duration.
Currently, pacemakers are powered by batteries which have a duration of a few years. This requires that patients undergo surgery regularly in order to keep their pacemakers in working order. According to M. Amin Karami, the lead researcher, “Many of the patients are children who live with pacemakers for many years,” he said. “You can imagine how many operations they are spared if this new technology is implemented.”
The piezoelectric pacemaker is about the size of a regular battery, and has been tested extensively. According to Karami, it was able to generate create enough electricity from as few as 20 beats per minute, or as many as 600, to maintain a healthy heartbeat. However, there are still likely to be many years of testing before it is approved for medical use.
But most exciting is the implications this pacemaker has for other biomedical devices such as dispensers and sensors – all of which would live under our skin and be powered by our body heat and movements. Image if everyone was born with a defibrillator/pacemaker implanted in their chest. Surely, death from heart disease would drop substantially, and people would even be able to jack their heart rate up in emergency situations.
Check out this video of the piezoelectric pacemaker in action.
Wind 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.
These 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.
The 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:
Stories by Williams 