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In today's odd science news, researchers have shown that they can produce electricity by evaporating water from a chunk of soot. The research falls into the category of systems that extract electricity from waste energy around us—kind of like generating electricity from swaying buildings or powering your watch from your own movements. But this was a result that I did not expect.
The experiments that make up the new work are so simple that pretty much anyone can do them themselves. Take a hydrocarbon of choice and set it on fire so that it burns with a yellow flame. Then hold a bit of glass in the flame so that it gets covered in soot. Afterward, expose the carbon to an atmospheric plasma. Tape some electrodes to the carbon and then lower it into some water.
The porous carbon drags water into itself through capillary forces, and when the water later evaporates from the carbon surface, electricity is generated. Not much, admittedly, at 53nW per square centimeter, but still enough to raise eyebrows.
It turns out that there is a commonly known mechanism that could cause this effect. Water always has some ions in it, and as it flows, it drags these ions along. So you get an electric current associated with the flow of water. In this case, the flow is induced by evaporation, but you could get the same effect by making the water flow downward via gravity.
Oddly, however, that flow isn't generating most of the electricity. By controlling where the evaporation could take place and measuring the current due to flow only, the researchers behind these experiments determined that the streaming water contributed about one-fifth of the total voltage.
Read more here. (Ars Technica)
The experiments that make up the new work are so simple that pretty much anyone can do them themselves. Take a hydrocarbon of choice and set it on fire so that it burns with a yellow flame. Then hold a bit of glass in the flame so that it gets covered in soot. Afterward, expose the carbon to an atmospheric plasma. Tape some electrodes to the carbon and then lower it into some water.
The porous carbon drags water into itself through capillary forces, and when the water later evaporates from the carbon surface, electricity is generated. Not much, admittedly, at 53nW per square centimeter, but still enough to raise eyebrows.
It turns out that there is a commonly known mechanism that could cause this effect. Water always has some ions in it, and as it flows, it drags these ions along. So you get an electric current associated with the flow of water. In this case, the flow is induced by evaporation, but you could get the same effect by making the water flow downward via gravity.
Oddly, however, that flow isn't generating most of the electricity. By controlling where the evaporation could take place and measuring the current due to flow only, the researchers behind these experiments determined that the streaming water contributed about one-fifth of the total voltage.
Read more here. (Ars Technica)
