Efficient Nanopillar Solar Cells….and Cheap Too…..!!

Researchers at the University of California, Berkeley, have made a new kind of solar cell by growing an array of upright nanoscale pillars on aluminum foil. They make bendable solar cells by encapsulating the entire cell inside a transparent, rubbery polymer. The design, the researchers suggest, could lead to solar cells that cost less than conventional silicon photovoltaics.

The nanopillars allow the researchers to use cheaper, lower-quality materials than those used in conventional silicon and thin-film technologies.

So the cost would decrease 10 folds when it will be made on a big scale.

The solar cells are made of uniform 500-nanometer-high pillars of cadmium sulfide embedded in a thin film of cadmium telluride. Both materials are semiconductors used in thin-film solar cells.

In an online Nature Materials paper, it was shown that the cells have an efficiency of about 6 percent in transforming sunlight into electricity as compared to other nano pillars grown with expensive materials which have an efficiency of 2%.

In conventional cells, silicon absorbs light and creates free electrons, which need to get to the electrical circuit before they get trapped at defects or impurities in the material. This requires extremely pure, expensive crystalline silicon to achieve the most efficient photovoltaic devices.

The nanopillar design splits up silicon’s duties: the material surrounding the pillars absorbs light and creates electrons, and the pillars transport them to the electrical circuit. This increases efficiency in two ways. The closely packed pillars trap light between them, helping the surrounding material absorb more. The electrons also have a very short distance to travel through the pillars, so there are fewer chances of their getting trapped at defects. That means you can use low-quality, less expensive materials.

The researchers also intend to try other semiconductor materials for the pillars and surrounding material. The fabrication process is compatible with a wide range of semiconductors, and other combinations could increase the efficiency.

Now Screen movies using your phone….!!

A new mini projector prototype could see mobile phone users hosting impromptu movie screenings on makeshift screens such as white towels or walls… without killing the battery. Unlike conventional projectors the prototype doesn’t need an additional illumination system. Instead it relies on a lens system to project images produced by an OLED onto a wall or other flat surface.

Operating without an extra light source offers the dual benefits of reduced size and energy requirements. The prototype is 2.5 cm long, has a diameter of 1.8 cm and needs very little energy. This means the projector could be easily integrated into a mobile phone or PDA without overtaxing the devices’ battery.

Currently the prototype’s OLED display produces a monochrome image with a brightness of 10,000 candelas per square meter, and color images about half that level. By way of comparison, a computer monitor generates about 150-300 candelas per square meter.

The lenses used in the prototype are made of glass, but the development team is working on an optical system that uses plastic lenses. This is because plastic lenses can be embossed, so they can be produced in larger quantities more simply and cheaply than glass lenses.

The mini projector was developed by research scientists at the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena in cooperation with their partners in the EU project HYPOLED.

Source: Fraunhofer Institute

Pocket Cellphone Charger

Product: Fuel-cell recharger

Cost: Initially between $100 and $200; cartridges will cost between $1 and $3.

Company: Lilliputian Systems

Solid-oxide fuel cells can generate electricity using a range of readily available fuels. But because they run very hot–often above 1,000 ºC–they typically require insulation that makes them bulky. A new version employs an insulation technique that keeps the finished device as small as a pack of playing cards. The gadget, which could help keep electronic devices humming on long flights or hikes, runs on cheap butane cartridges; one cartridge packs enough power to recharge a smart phone 20 times. Swap out the cartridge, and it’s ready for 20 more charges. The device is scheduled to go on sale next year.

Source

Quantum-Dot Lighting – A New age of LED lamps

Product: Array lamp with Quantum Light optic

Company: Nexxus Lighting, QD Vision

Light-emitting diodes (LEDs) are highly efficient, but they can’t directly produce white light. Though a blue LED can be coated with a phosphor that alters some wavelengths to yield a whitish mix, the resulting light has a bluish cast, and some energy is wasted as heat in the process. A new LED lamp avoids this problem by using an optic coated with quantum dots–bits of semiconductor material a few nanometers in diameter. When excited by a light source, the dots radiate light in wavelengths that vary according to their sizes. The optic–coated with dots in specific sizes and ratios–appears orange when the light is off (left) but radiates white light when the underlying blue LED is on (right). The result: LED lamps that are 50 percent more efficient and produce better-quality white light.

Because the Nexxus Lighting Array lamps with Quantum Light™ are compatible with a standard, screw-in Edison base, they can easily replace incandescent and halogen lamps in existing downlight fixtures. Just in the US, the DoE estimates, the number of down lights and track heads with Edison base lamp installations equal over 139 million in commercial applications and over 262 million in residential lighting applications. Both companies expect that commercial availability of their high efficiency lamps with high color quality will overcome a major barrier to LEDs and will accelerate the penetration of LEDs in the $4 billion U.S. lamp market. The potential impact on the environment could be significant, a full conversion to LEDs of existing downlights and trackheads in the US (approximately 10% of US fixtures) represents an annual savings of more than 35 billion KW hours (nearly $4 billion), which is the equivalent of nearly 6 power plants or more than 60 million barrels of oil per year.

Sources: Nexxus Lighting, QD Vision

Lithium-sulfur batteries Thrice power storage than that of lithium-ion

A research team from the University of Waterloo has synthesized a prototype of a lithium-sulphur rechargeable battery that, thanks to its peculiar nanoscale structure, can store three times the power of a conventional lithium-ion battery in the same volume while being significantly lighter and potentially cheaper to manufacture.

When it comes to reducing our carbon footprint, a clean, long-lasting rechargeable battery could have enormous benefits in a wide range of applications, from efficient energy storage to clean transportation.

Pros and Cons of lithium-sulfur cells

Pros

•Delivers much higher energy densities while reducing the cost of the materials used:

•The composite material synthesized by Nazar’s team can supply as much as 84 percent of the theoretical capacity of sulphur – three times the energy density of lithium transition cathodes. This should account for significantly more efficient batteries which will be lighter as well.

•The basic raw materials for the positive electrode (sulfur and carbon) are very inexpensive.

Cons

•In terms of safety, because lithium-sulfur batteries typically employ a negative electrode comprised of metallic lithium, there could be safety concerns if the electrode is not adequately protected by a passivating layer. However, the research team seems optimistic that this won’t be impossible to overcome.

•The costs associated with processing, electrolyte, fabrication, etc could be high, still that is highly dependent on the optimization of the materials and the battery configuration.

•Capacity fading can be more of an issue, along with lower volumetric energy and those need to be tackled more fully.

Via

Touch Sight

Touch Sight is a digital camera for visually impaired people. Easy to use, it includes a unique feature which records sound for three seconds after pressing the shutter button. The user can then use the sound as reference when reviewing and managing the photos. Touch Sight does not have an LCD but instead has a lightweight, flexible Braille display sheet which displays a 3D image by embossing the surface, allowing the user to touch the image. The sound file and picture document combine to become a touchable photo that is saved in the device and can be uploaded to share with others–and downloaded to other Touch Sight cameras.

Design: Samsung Design (China)

The SoundBulb

There are various lighting and/or sound products available in the market, but most of them are very direct and serves a particular task efficiently. SoundBulb is an outcome of a competitive product market research across a wide range of exciting lighting/sound products. This concept utilizes both lighting and sound into one product and the final design features a bulb like shaped speakers that can be enhance the décor of your household as well as increase the functionality. The combination brings together the sophistication, ambient and elegance of lighting and sound in order to form a product that tickles our sense more than a single way.

The SoundBulb acts as a wireless speaker and a lighting device simultaneously. The bulb utilizes LED lights for illumination and Bluetooth to stream audio from a compatible computer or gadget wirelessly. The volume is controlled by twisting the bulb’s outer ring, while the on/off switch for the wireless receiver is located on the other side. The wireless speakers are powered from the electric socket it’s plugged to.

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Dyson Human Energy Harvesting Bracelet

Dyson Energy Bracelet is a gadget that uses Seebeck effect to harness energy and power your mobile phones for a few precious minutes more, when you desperately need it. Lemme explain a bit: The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. This typically includes three separately identified effects, the Seebeck effect, the Peltier effect, and the Thomson effect. This is coz three different guys discovered it around the same time, however Peltier–Seebeck and Thomson effects are reversible and Joule heating is not.

The designers explain:

Thanks to the Seebeck effect, the temperature difference between the surface which touch the skin and the other which is in the ambient air allows to produce electricity that is stocked in a battery. When the user needs to recharge a mobile device, he plugs it into the Dyson Energy through a micro-USB port (universal connector imposed to constructors in 2012) and can have some additional minutes in use.

Firstly, we have tested the Peltier element in its most common use: i.e. the creation of heat and coldness on the same component (Seebeck effect), and we have noticed that there was electricity production. We have met an engineer who allowed us to evolve on our project while explaining us that there was not possible to plug the elements serially. Therefore, we chose to work with only one element. As a result of many calculations, we have validated this technology payoff regarding our concept. For instance, some hours are sufficient to power its cellphone for a dozen minutes of communication.

Designers: Mathieu Servais, Camille Lefer, Clément Faydi & Mickaël Denié