Aerogel, what's this ?

Aerogel has been invented in the 30's but was actually improved and used by Nasa in last 3 decades. It is the thermal isolator invented. It is now open and you can SIT now.

FESTO : inspired by nature

Who killed the electric car ?

"Who killed the electric car" is a 2006 (documentary) movie starring Mel Gibson, Tom Hanks and many others

Super diamonds (National Geographic)

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Cold Fusion ?? Do it yourself !!! (APE stands for "Asymmetrical Plasma Electrolysis")

Source from http://jlnlabs.online.fr/cfr/ape/

Harry Potter's invisibility cloak becomes a reality thanks to plasmon

The dream of every Harry Potter fan of owning an invisibility cloak seems to have come true with researchers at the University of Maryland developing what can be termed as the world’s first true invisibility cloak – a device able to hide an object in the visible spectrum of light.

Professor Christopher Davis, research scientist Igor Smolyaninov, and graduate student Yu-Ju Hung at Maryland's A. James Clark School of Engineering have used plasmon technology to create the world's first invisibility cloak for visible light.

They have used the same technology to develop a revolutionary superlens microscope that enables scientists to see details of previously undetectable nanoscale objects.

The invisibility cloak refracts the light that strikes the object, so that the light moves around and past the cloak, reflecting nothing, leaving the cloak and its contents ‘invisible.’

The cloak consists of a two-dimensional pattern of concentric rings created in a thin, transparent acrylic plastic layer on a gold film. The plastic and gold each have different refractive properties.

The structured plastic on gold in different areas of the cloak creates ‘negative refraction’ effects, which bend plasmons, electron waves generated when light strikes a metallic surface under precise circumstances, around the cloaked region.

This manipulation leads the plasmon waves to appear to have moved in a straight line. In reality they have been guided around the cloak much as water in a stream flows around a rock, and released on the other side, concealing the cloak and the object inside from visible light. The invisibility is not absolutely perfect because of energy loss in the gold film.

Researchers achieved this invisibility under very specialized conditions. The cloak is just 10 micrometers in diameter; by comparison, a human hair is between 50 to 100 micrometers wide. Also, the cloak uses a limited range of the visible spectrum, in two dimensions.

Extending the cloak to three dimensions would be a significant challenge because researchers would need to control light waves both magnetically and electronically to steer them around the hidden object. The technology initially might work only for small objects of specific controlled shape.

Researchers have also used plasmonics to develop superlens microscopy technology, which can be integrated into a conventional optical microscope to view nanoscale details of objects that were previously undetectable.

The superlens microscope could one-day image living cells, viruses, proteins, DNA molecules, and other samples, operating much like a point-and-shoot camera. The new technology could revolutionize the capability to view nanoscale objects at a crucial stage of their development. The team believes they can improve the resolution of their microscope images down to about 10 nanometers, one ten thousandth of the width of a human hair.

A large reason for the success of the group's innovations in both invisibility and microscopy is that surface plasmons have very short wave lengths, and can therefore move data around using much smaller-scale guiding structures than in existing devices.

These small, rapid waves are generated at optical frequencies, and can transport large amounts of data. The group also has made use of the unique properties of metamaterials, artificially structured composites that help control electromagnetic waves in unusual ways using plasmonic phenomena.

The various applications the group has derived from their plasmonics research is an example of the ingenuity of researchers approaching new and dynamic technologies that offer broad and unprecedented capabilities.

http://www.sciencedaily.com/releases/2007/12/071218192009.htm

http://www.abc.net.au/science/articles/2003/06/12/872457.htm

http://www.cnrs.fr/insis/recherche/actualites/invisibilite.htm

DRONES : Do It Yourself !

For more informations :

http://diydrones.com

http://www.virtualrobotix.com/

What is the future for batteries : beta-voltaic ?

Do you know Tritium ? It is an isotope of hydrogen (H rated 3), ie, an atom with neutrons more or less in the nucleus - two more neutrons in this case.

The particularity of tritium is that it is a radioisotope, a word which is not afraid to say it is radioactive. Oh, nothing to do with uranium-235, do not worry. It degrades slowly by emitting beta-minus decay radiation - in other words, it emits electrons.

Moreover these electrons can recover in semiconductors. Result ? This makes an electric current.

Here is beta-voltaic system. 

principle of Tritium battery

It's been a while since we worked on this : the principle was discovered fifty years ago, and they are already feeding of satellites as per their long-term life, it has been used also for cardiac stimulators. Because the strength of this power is that his life is closely linked to the degradation of the selected element : electricity production is continuous, decreasing gradually until complete degradation.

from http://www.betavoltaic.co.uk

It is reasonable to expect that a beta-voltaic battery tritium produces electricity for thirty years.

Today, following research of the U.S. Air Force was announced in the coming years beta-voltaic cells for cell phones or laptops.

Some will worry about bringing sources radiating into their lives. Hopefully, tritium is kind enough not to issue any other radiation than beta emission, which are not harmful and easily controllable (single aluminum foil easily stop them, as well as human skin). Besides, you may have some already in your environment : tritium is commonly used in the manufacture of luminescent watch (it replaced radium for this use, which emitted more gamma carcinogen radiation).

Another advantage : once emptied, the battery would contain no more radioactive element and would be inert and harmless : the degradation of tritium produces helium 3, perfectly stable. In fact, it would even be much cleaner than the current batteries containing heavy metals.

Then, is betavoltaic battery the panacea for computers, without being to be charged until 2050 ?

> not quite sure: the production of tritium is not without issues.
The size of the tritium atom (remember that hydrogen is the smallest of all atoms) makes it very difficult to store: it has a tendency to penetrate most materials. Also, emission is divided by two every decaying period (12.32 years), which means the battery must be over-sized at the beginning of its life in order to be still usable at its end of life.

Still, this line of research appears very promising, the main issue being miniaturizing sufficiently the gaz container to fit in a laptop.


For instance, porous silicium and 3D shaped silicium will help to overgo these limitations

Nanowatt batteries, lasting 20 years. Credit from http://www.citylabs.net

More about betavoltaic :
http://peswiki.com/index.php/PowerPedia:BetaVoltaic
http://www.livescience.com/technology/091209-nuclear-batteries.html

Direct Carbon Fuel Cells (DCFC) : the ultimate biomass conversion technology ?

Did you say converting carbon directly into electricity without "burning" it ???

Yes ! this is now possible

Moreover :

• the process presents an overall efficiency of 70% which is a very good performance compared to traditional burning+heat plants (35% maximum according the Carnot theoretical thermodynamics limitation)
• environment friendly as it is CO2 capture-ready, and reduces emission by 50% prior to sequestration (the total quantity of CO2 emission is half for the same quantity of energy produced,  the sequestration process is easier, is more secure and is also cheaper to achieve)
• no water required all along the process (no steam, no cleaning, etc.)

Operations began in 2006 at Stanford University. Tests are continuing on various grades of coal, wheat and rice straw, corn stover and wood.

diagram of the fuel cell process

Made of a core of ceramic tubes, the system operates at 900°C and emit only a pure stream of CO2, ready to be captured without the capital and energy cost of separation from nitrogen. Ash, sulfur, lead, mercury and other solids would not be released to the atmosphere but would be carried to landfills or re-cycled.

In the production of distributed base-load electricity, coal or biomass is fed into the base of the system. The carbon in the coal or biomass is gasified without water into carbon monoxide by the re-circulating carbon dioxide. That is: C+CO2= 2(CO). The CO then moves up the inside of the ceramic tubes. At a temperature of 900 degrees Centigrade the oxygen in the air on the outside of the cell walls is under pressure to cross the barrier and oxidize the CO on the other side. It cannot cross as an oxygen molecule but only as an oxygen ion. So the O2 picks up four electrons from the utility grid, crosses the barrier, bonds with the CO and sheds the electrons, creating the electric current. That reaction is 2(CO)+O2ion= 2(CO2)+4e.

That's simpler and twice as efficient as a 20th century coal power plant.

The system is compact and modular, groups of directcarbon Fuel Cell systems, each with the footprint of a forty-foot cargo container, can be grouped for generation of electricity in the megawatt range.

Source : directcarbon

A fuel cell is an electrochemical device that efficiently converts a fuel's chemical energy directly to electrical energy without burning the fuel. However, instead of using gaseous fuels, as is typically done, DCFCs use aggregates of extremely fine (10- to 1,000-nanometer-diameter) carbon particles distributed in a mixture of molten lithium, sodium, Yttria-stabilized zirconia or potassium carbonate at a temperature of 600 to 850°C. The overall cell reaction is carbon and oxygen (from ambient air) forming carbon dioxide and electricity

The reaction yields can reach 80% of the carbon–oxygen combustion energy as electricity, yet no burning of the carbon takes place. DCFCs for stationary applications provide up to 1 kilowatt of power per square meter of cell surface area — a rate sufficiently high for practical applications. Some developers are designing DCFCs for mobile applications that can deliver energy densities in the range of 1,000–2,000 Wh/kg, far higher than any advanced battery.

Source : Mongabay


Conclusion : this is a very promising technology !

PetMan, the walking robot

Biped robot that balances dynamically using a human-like walking motion.





Fore more information : http://www.bostondynamics.com

BigDog : Advanced Robotics

With a sense of balance seemingly flawless and a quasi natural, BigDog robot is probably the most compelling and fully autonomous robot ever made.

Hardware Scheme of the BigDog robot

Developed by Boston Dynamics under a program funded by DARPA (Defense Advanced Research Projects Agency), BigDog has been primarily designed to test the possibilities of natural locomotion through various more or less rugged terrain and under various degrees of tilt .

With 1 meter long and 75 centimeters tall and weighing 110 kg, the robot is supported by four servomotors equipped with jointed legs and 50 sensors found in other parts of the body whose duties extend from the control of the load carried (up to 170 kg!) recognition of the surrounding terrain. Its speed reached 6.5 km per hour and it readily crosses slopes of 35° inclination, positive as negative.

Scheme of the software logic

Its movement is controlled by an onboard computer that receives information from multiple sensors of the craft. Navigation and balance are also managed by this computer.

Big Dog is powered by a one cylinder two-stroke 15cv engine, similar to a kart, which spuns at 9000 rpm. The engine drives a hydraulic pump which itself led actuators legs. Each leg has four actuators (two for the articulation of the "hip", one for the "knee" and the "ankle") for a total of 16. Each actuator includes a hydraulic cylinder, a servo-hydraulic valve, a position sensor and a force transducer. The electronic board is fairly modest. A rugged PC/104 card with a processor of Pentium 4 class running QNX. BigDog is also equipped with laser gyroscope and a stereo vision system.

BigDog demonstrates its ability to avoid falling under the effect of external disturbance or imbalance on slippery ground. His behavior under any circumstances is remarkably natural :

Source : http://www.bostondynamics.com

3D vision : how the BigDog locates himself in space

Less than half the Earth's landmass is accessible to existing wheeled and tracked vehicles. But people and animals using their legs can go almost anywhere. The mission given to Boston Dynamics is to develop a new breed of rough-terrain robots that capture the mobility, autonomy and speed of living creatures. 

Such robots will travel in outdoor terrain that is too steep, rutted, rocky, wet, muddy, and snowy for conventional vehicles. They will travel in cities and in our homes, doing chores and providing care, where steps, stairways and household clutter limit the utility of wheeled vehicles. Robots meeting these goals will have terrain sensors, sophisticated computing and power systems, advanced actuators and dynamic controls.