Scientists have figured out how to harness Brownian motion – literally the thermal energy of individual molecules – to make electricity, by cleverly connecting diodes up to pieces of graphene, which are atom-thick sheets of Carbon. The team has successfully demonstrated their theory (which was previously thought to be impossible by prominent physicists like Richard Feynman), and are now trying to make a kind of micro-harvester that can basically produce inexhaustible power for things like smart sensors.
The most impressive thing about the system is that it doesn’t require a thermal gradient to do work, like other kinds of heat-harvesting systems (Stirling engines, Peltier junctions, etc.). As long as it’s a bit above absolute zero, there’s enough thermal energy “in the system” to make the graphene vibrate continuously, which induces a current that the diodes can then pump out.
Original journal link: https://journals.aps.org/pre/abstract/10.1103/PhysRevE.108.024130
Holy shit that’s actually really big news even if any practical applications are very far off. As someone said in a comment below, this is essentially Maxwell’s Demon, which as I understand it violates the second law of thermodynamics-- that entropy must always increase. In other words, “waste heat” is no longer truly a waste; we can extract energy from heat without a temperature gradient! I’ll be watching for more news on this (both for confirmation and dispute) in the future. If this does turn out to be true, it’s almost certainly Nobel Prize worthy.