Well if this works as they say I’d guess this isn’t working without a temperature gradient, just a very small one that is found throughout the molecules in the graphene sheet itself, hence why this needs to be above zero Kelvin and why I’d guess they are only targeting micro/nano sensors to power as they can’t ever scale this beyond the inherent gradient present in graphene. I’m not a physicist so don’t take my word as the gospel but at the same time I don’t see why this is ruffling so many feathers when it clearly can’t scale past these smaller voltages that they are targeting, which seems to hint at this just being a way to take advantage of the natural heat loss on graphene for small powered devices.