Using a match to recharge your phone? // EIT Digital


Using a match to recharge your phone?

A time-lapse series of photos, progressing from top to bottom, with a coating of sucrose (ordinary sugar) over a wire made of carbon nanotubes is lit at the left end, and burns from one end to the other. As it heats the wire, it drives a wave of electrons along with it, thus converting the heat into electricity. Credit: MIT

Back in 2010 a team of scientists at MIT discovered that heating a carbon nanotube generates an electrical current.

This was a completely new phenomenon, never before detected, and they called it thermopower waves. It had a scientific interest (scientists are a curious breed and anything that is new draw their attention) but no practical implication. The amount of current generated was so minuscole that it was completely useless.

Just 5 years have gone by and the same team has now discovered a way to increase the yield of current produced to the same level of the one obtained by the best batteries we have today, an increase in performance of 10,000 folds. That is much better than the Moore's law and of the progress we saw in chemical batteries from the time they were invented.

What they did was to cover carbon nanotubes with a sugar coating. By lighting that sugar coating a heat wave propagates along the carbon nanotubes and this generates the thermopower waves that generate the electric current.  The efficiency is still very very low, only about 1% of the heat energy gets converted into electrical energy...

Interestingly, you end up producing electricity without using any environment hazardous substance, like the lithium you have in your batteries today. Just some sugar...

Mind you, we are still far away from a commercial application but time flies and you should not be surprised if in the next decade you will carry with you a slip of papers made of nanotube that you can light up with a match to generate power to recharge your cell phone... Science fiction, probably, but with credible science roots!

Author - Roberto Saracco
