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Self-Assembling Photovoltaic Tech From MIT
telomerewhythere writes "Michael Strano and his team at MIT have made a self-assembling and indefinitely repairable photovoltaic cell based on the principle found in chloroplasts inside plant cells. 'The system Strano's team produced is made up of seven different compounds, including the carbon nanotubes, the phospholipids, and the proteins that make up the reaction centers, which under the right conditions spontaneously assemble themselves into a light-harvesting structure that produces an electric current. Strano says he believes this sets a record for the complexity of a self-assembling system. When a surfactant is added to the mix, the seven components all come apart and form a soupy solution. Then, when the researchers removed the surfactant, the compounds spontaneously assembled once again into a perfectly formed, rejuvenated photocell.'"
Per the article it's not nearly as biological as "plant-inspired" makes it sound.
They are using the photovoltaic effect to generate electricity on some set of proteins. Then carbon nanotubes conduct the electricity from the proteins to a common circuit. They are using phospholipids (whatever phospholipids are) along with the nanotubes to coerce proper alignment between the nanotubes and the proteins in the photovoltaic reaction sites.
The combination works pretty well (40% efficiency with sparsely populated functional structures in the solution for the prototype) until it starts to break down. The inspiration from plants is mainly that they can introduce a substance (a surfactant more specifically, although the blurb doesn't specify which) that breaks the stuff down fast, then filter the surfactant out through a membrane and the working portion self-assembles again at full efficiency.
It's this repeatable self-assembly that was biologically inspired, and it's probably necessary for high-efficiency photovoltaic solar cells since pretty much everything more efficient than silicon does break down over time. By not just accounting for the breakdown, but doing it early and often and performing a repair phase through self-assembly, it is hoped they can have high efficiency solar cells with long lifespans.
That's gleaned from TFA, which isn't much longer than what I wrote.
is at http://web.mit.edu/newsoffice/2010/self-healing-solar.html
No but many are more evolved then us. Plants have been around evolving on land much longer then the first bug left the oceans. They are quite adapted to their environment. Now humans and mammals are not so evolved but our evolutionary path took a different way where a more organized central nervice system took presendance over energy gathering.
That's not quite the best description of evolution. It isn't a race to some endpoint, there really isn't much that can be classified as 'less evolved or more evolved' unless you slice the requirements so thin that only one organism could survive based on such criteria and therefore make the whole concept of evolution meaningless. Let's say a landslide washes a very niche species of plant into the ocean where the saline content promptly kills the entire species. Does that make a salmon more evolved since it didn't die?
And for that matter, unless we assume some multiple genesis theory for life on Earth, every species today has been subject to evolutionary forces for the exact length of time as any other species.
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