This research from the University of Arkansas claims to harvest electrical energy from thermal vibrations in a sheet of graphene:
The idea of harvesting energy from graphene is controversial because it refutes physicist Richard Feynman's well-known assertion that the thermal motion of atoms, known as Brownian motion, cannot do work. Thibado's team found that at room temperature the thermal motion of graphene does in fact induce an alternating current (AC) in a circuit, an achievement thought to be impossible.
From what I can tell, this is morally equivalent to putting an atomic-scale condenser microphone in a warm gas and expecting the brownian motion of the gas to induce a harvestable energy signal, even if it's just white noise. The problem I have with this result is the following:
Suppose we connect the resulting circuit to an incandescent light bulb. The researchers claim that the temperature of the graphene and circuit don't change. But I guarantee you the light bulb will. So, we are left with two possibilities:
- The system spontaneously increases in temperature, as the graphene circuit extracts free energy and then releases it via the light bulb.
- The graphene transducer cools its immediate environment (how could it not, if we are still conserving momentum, and the circuit is converting the momentum of the graphene into electrical current), and the light bulb re-heats it by the same amount (minus any thermal losses in the circuit).
(2) is problematic because the graphene is creating a cold reservoir ex nihilo, is it not? I mean, it's doing that without an input of energy, which should not be possible, right?
Of course, all of this becomes possible if the circuit only works under non-equilibrium conditions, and it's really harvesting transient thermal gradients that appear in its environment. But the story certainly does not give that impression. Thoughts?
