Monday, 7 September 2015
Wednesday, 31 December 2014
Tuesday, 18 November 2014
Austrian designer Kristof Retezar has invented a new device for your bike that collects the moisture contained in the atmosphere, condenses it and stores it as fresh drinking water.
A new self-filling water bottle has been invented that can not only serve as a nifty device for long bike tours and races, but could also offer a new method of fresh water collection in parts of the world where groundwater sources are hard to come by.
Developed by industrial designer Kristof Retezar from Austria’s University of Applied Arts, the new device - called the ‘Fontus’ - works best in humid weather, which allows it to condense the moisture in the air into safe, fresh drinking water. Experiments have shown that under the right weather conditions, it can produce 0.5 Litres of water in just under an hour.
"My goal was to create a small, compact and self-sufficient device able to absorb humid air, separate water molecules from air molecules and store water in liquid form in a bottle,” says Retezar at the James Dyson Award website.
Retezar says he was inspired to invent the device as something that could be beneficial to some of the 2 billion people in more than 40 countries that live in regions where clean and safe sources of water are scarce. According to the UN, by the year 2030, 47 percent of our global population will be living in areas of high water stress. So he decided to take a 2,000-year-old technology - ancient civilisations from Asia and Central America were some of the first to employ it - that taps into some of the 13,000 kilometres cubed of fresh water held in the Earth’s atmosphere.
Retezar explains how it works at the James Dyson Award website:
In order to achieve condensation, one must cool hot, humid air down. The device has a small cooler installed in its centre called Peltier Element. This cooler is divided in two: When powered by electricity, the upper side cools down and the bottom side gets hot. The more you cool the hot side down, the colder the upper side will get. Consequently, these two sides are separated and isolated from each other.
The air enters the bottom chamber at a high speed when moving forward with the bike and cools the hot side down. Moreover, when the air enters the upper chamber it is stopped by little walls perforated non-linearly, reducing its speed in order to give the air the needed time to lose its water molecules.
Once the water molecules have been extracted, the droplets flow through a pipe and accumulate in a bottle. This bottle can be easily loosened from its holder for drinking, and any kind of PET 0.5 L bottle will fit.
The Fontus has been entered into theJames Dyson Award, which is an annual, international design competition, and a win could provide Retezar with the capital to jettison his design to the market.
Tuesday, 11 November 2014
Friday, 19 September 2014
Your next smartphone or electric vehicle might be powered by a nuclear battery instead of your usual lithium-ion cell thanks to a breakthrough made by University of Missouri researchers. This is bad news for those of you who think that WiFi signals are bad for your health — especially if they’re received by a smartphone situated near your head or gonads — but great news for all of the people who value all-day battery life ahead of increased radiation exposure. The world could probably do with reduced fertility rates anyway, right?
First, just to put your mind at rest: This nuclear battery doesn’t contain a mini nuclear fission reactor — that would be insane (at least given our current grasp of nuclear power generation, anyway). Instead, this battery, developed by Baek Kim and Jae Kwon at the University of Missouri, uses the betavoltaic process to generate electricity. A betavoltaic device, as the name implies, is fairly similar a photovoltaic device — but instead of generating electricity from photons, it generates electricity from beta radiation — i.e. high-energy electrons that are emitted by radioactive elements. A betavoltaic device is constructed in almost exactly the same way as a photovoltaic cell: a piece of silicon (or other semiconductor) is wedged between two electrodes, and when radiation hits the semiconductor it produces a flow of electrons (voltage, electricity).
“But surely having a battery, and thus a mobile device, packed full of radioactive material is a bad idea” I hear you say. And usually, yes, you’d be right. What makes a betavoltaic battery somewhat safe is that beta radiation can be easily stopped with a thin piece of aluminium; gamma radiation, on the other hand, has so much penetrative power that it can only be stopped by a big lump of lead (or other dense metal). This doesn’t mean that beta radiation in itself is safe — it can cause cancer and death — but it’s much easier to control. Just make sure the betavoltaic nuclear battery casing is more than a couple of millimeters thick — and don’t drop it. Ever.
Anyway, back to the University of Missouri’s battery. Basically, Kim and Kwon’s nuclear battery consists of a platinum-coated titanium dioxide electrode, water, and a piece of radioactive strontium-90. Strontium-90 (Sr-90) radioactively decays with a half-life of 28.79 years, producing an electron (beta radiation), an anti-neutrino, and the isotope yttrium-90. Y-90 itself has a half-life of just 64 hours, decaying into more electrons, anti-neutrinos, and zirconium (which is stable). The best thing about using strontium-90 as a fuel is that it produces almost no gamma radiation — so, as far as radioactive materials go, it’s pretty safe and easy to handle. (Still, there’s no avoiding the fact that it’s used extensively in medicine, both for radiotherapy of cancer, and as a radioactive tracer.)
While betavoltaic batteries are fairly old hat — they powered some of the earlier pacemakers, before more advanced chemistries such as lithium-ion arrived — the Missouri researchers say that their addition of water is a key breakthrough. Not only does water absorb a lot of the energy of the beta radiation (in high quantities it’s damaging to the betavoltaic semiconductor), but the beta radiation also splits the water molecules, producing free radicals and electricity.
“Water acts as a buffer and surface plasmons created in the device turned out to be very useful in increasing its efficiency,” Kwon says. “The ionic solution is not easily frozen at very low temperatures and could work in a wide variety of applications, including car batteries and, if packaged properly, perhaps spacecraft.” [Research paper: doi:10.1038/srep05249 - "Plasmon-assisted radiolytic energy conversion in aqueous solutions"]
Ultimately, even if beta radiation can be quite easily contained, I doubt we’ll ever see commercial nuclear batteries. Those headlines about exploding lithium-ion batteries are already scary enough; I can’t imagine Apple or Samsung will ever open themselves up to even worse headlines/lawsuits. (“Smartphone owner dies from acute radiation sickness after dropping his phone”.) There’s also the distinct possibility of terrorists creating a dirty bomb from all of that strontium-90 (which itself isn’t cheap, incidentally).
For now, nuclear batteries will probably only be used in military and space applications, where extreme longevity outweighs any risks. Still, it’s nice to dream of a smartphone or other mobile device that never once needs recharging…