Only in the load resistor. Electron flux in the graphene membrane appears to be solely due to geometry. This curvature does not necessarily need to be buckled via heat energy. It could be mechanical or electrical, if I understand things correctly...

More detail in this video clip with UArk's Paul Thibado:

https://www.youtube.com/watch?v=wrleMqm3HiU

I think what this research opens up is the possibility of "optimal" harvesting. There is some resonant frequency, some circuit configuration yet to be discovered that is perhaps self-sustaining. They've chosen "stochastic thermodynamical" circuits because its low hanging fruit. But it seems really exciting to me. Almost like a third class of energy production after solar and hydrogen (where 99% of research funds are allocated). Ocean wave energy harvesting perhaps?

In any case, congrats to the researchers on their painstaking hard work ;)

Fluctuation-induced current from freestanding graphene: toward nanoscale energy harvesting

https://arxiv.org/abs/2002.09947

Yea that video is helpful and it looks like mechanical energy or thermal could be used to deform the graphene film to do some work on that film which them stores it. So it seems like what’s happening is that thermal energy is being used to put energy into the free standing graphene lattice. Then as it extends in length due to the film heating, it stores energy almost like inflating a balloon, then it touches one of the electrodes nearby and the electrons in this unique material transfer charge to the other electrode and causes the film to contract so a portion of the charge was transferred away, and it contracts then can repeat the process. So it’s a small motor that harvests either mechanical or thermal energy. But given the tiny size, it would seem like thermal might be the dominant thing since the membrane would probably need some sort of mass to benefit from random movements. Or the graphene would need to be extremely flexible. But not totally sure..

This does sound promising. Is it possible to run this process in reverse a la a heat pump to create an AC with no moving parts? Or is this purely a one way process?

I'd say Joule heating is the reverse of this process: https://en.wikipedia.org/wiki/Joule_heating#Microscopic_desc...

Peltier coolers are probably in line with what you're suggesting, but they're not super efficient.

I was hoping for an alternative to those. They are neat but with such low efficiency they aren’t super useful.

I'm completely out of my area of expertise here (I can mostly follow the press release but I can't understand that much of the actual paper outside of the introduction), but your comment about resonant frequencies reminded me of of some recent research on layering graphene at a "magic angle" to produce special fractal moire patterns that have special physical properties. I wonder if that work can be combined with the work here. To a non expert like myself, it seems like there is a lot of really exciting research in this area at the moment.

Could they add this to waste heat pipes in power plants to extract more energy?

Thank you; awful title.