Speaking in Anaheim, California at the 241st National Meeting of the American Chemical Society, scientists have described the advanced solar cell, about the size of a playing card, which imitates photosynthesis.
It has long been a goal of scientists working towards sustainable energy to develop an artificial leaf. The device shows promise for a cheap source of electricity especially in third world countries, and it is thought that just one of them could power the average house in most developing nations.
Optically the device has however nothing in common with the natural counterpart. It is made from silicon, different electronic parts and several catalyst substances, which accelerate and start reactions that would otherwise not happen. To use the device it is placed in water, where it splits water into Hydrogen and Oxygen. These are then put into a fuel cell, which uses them to produce electricity. This fuel cell could be located on top of a house or next to it.
At the moment the artificial leaf is already about 10 times more efficient at carrying out photosynthesis than a natural leaf, but the team is confident that they can boost both efficiency and lifetime of the device significantly in the near future.
sorry guys for my rather long absence. I've been busy with school and I will probably be busy with school for quite some time to come. I'll go through all your blogs soon and catch up on what I missed.
Showing posts with label solar energy. Show all posts
Showing posts with label solar energy. Show all posts
Tuesday, 29 March 2011
Saturday, 26 February 2011
Researchers develop an artificial "Super-Skin"
Powered by stretchable solar cells, with integrated sensors that are sensitive enough to feel a fly touch down on it, while at the same time being as thin as normal skin, the artificial skin developed by Stanford researcher Zhenan Bao truly is a "Super-Skin".
At the foundation of the skin is an organic transistor, made from flexible polymers and other carbon based materials. Above that, to allow touches to be detected there is a rubber layer. When pressed it changes thickness which changes the amount of current that flows through the material below. This can then be translated into sensations.
There are also plans to add other kind of sensors to the material.
Especially detectors for chemicals are planned, and only recently they have managed to demonstrate the concept by detecting a specific type of DNA. This has applications especially in the medical science field, and a glove made from the material could help with the detection of diseases.
The applications for this type of material are endless, from replacing burned skin, to covering robotic prosthetic arms, or to allow robots to sense touches, it could be used for many things.
At the foundation of the skin is an organic transistor, made from flexible polymers and other carbon based materials. Above that, to allow touches to be detected there is a rubber layer. When pressed it changes thickness which changes the amount of current that flows through the material below. This can then be translated into sensations.
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| (Credit: Photos by L.A. Cicero) |
There are also plans to add other kind of sensors to the material.
"With artificial skin, we can basically incorporate any function we desire," said Bao, a professor of chemical engineering. "That is why I call our skin 'super skin.' It is much more than what we think of as normal skin."
Especially detectors for chemicals are planned, and only recently they have managed to demonstrate the concept by detecting a specific type of DNA. This has applications especially in the medical science field, and a glove made from the material could help with the detection of diseases.
The applications for this type of material are endless, from replacing burned skin, to covering robotic prosthetic arms, or to allow robots to sense touches, it could be used for many things.
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| Luke Skywalker's artificial hand. Things like this might soon be a reality. |
Thursday, 10 February 2011
Self Repairing Solar Cells?
Researchers at the University of Purdue have developed a solar cell that can repair itself.
The design exploits the unusual electrical properties of structures called single-wall carbon nanotubes, using them as "molecular wires in light harvesting cells," said Choi, whose research group is based at the Birck Nanotechnology and Bindley Bioscience centers at Purdue's Discovery Park.
Generally, the material works in much the same way as plants do. In a photochemical cell, a light absorbing dye, called "chromophore" degrades, much like the chlorophyll molecule in plant leaf cells.
The problem with normal solar cells is that they degrade over time. This new technology overcomes that problem in the same way that plants do: by continuously replacing the broken down molecules. In plants this happens approximately once every hour.
This design theoretically allows for indefinite use of a solar cell, as along as new chromophores are added.
The design works by using DNA strands and carbon nanotubes. DNA is used for its ability to sponatneously assemble in a structured way, and the carbon nanotubes are used as a backbone for the DNA to attach to.
Although the process is only in research stage and still far away from being used on an industrial stage, it shows promise, as most initial hurdles have already been overcome.
The design exploits the unusual electrical properties of structures called single-wall carbon nanotubes, using them as "molecular wires in light harvesting cells," said Choi, whose research group is based at the Birck Nanotechnology and Bindley Bioscience centers at Purdue's Discovery Park.
Generally, the material works in much the same way as plants do. In a photochemical cell, a light absorbing dye, called "chromophore" degrades, much like the chlorophyll molecule in plant leaf cells.
The problem with normal solar cells is that they degrade over time. This new technology overcomes that problem in the same way that plants do: by continuously replacing the broken down molecules. In plants this happens approximately once every hour.
This design theoretically allows for indefinite use of a solar cell, as along as new chromophores are added.
The design works by using DNA strands and carbon nanotubes. DNA is used for its ability to sponatneously assemble in a structured way, and the carbon nanotubes are used as a backbone for the DNA to attach to.
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| Diagram illustrating the principle behind how electricity is generated. hv stands for light, while e- stands for electricity/electrons being produced. (Credit: http://spie.org/) |
Although the process is only in research stage and still far away from being used on an industrial stage, it shows promise, as most initial hurdles have already been overcome.
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