A recent paper from an italian physicist proposes a simple Maxwell demon. A capacitor constituted of two dissimilar electrodes, an ordinary electrode and one with a low work function (cold cathode), charges itself when placed in a single thermal bath:
http://arxiv.org/abs/0904.3188
A chinese team also tempted similar but more complicated experiments, in which the electrodes were identical and the asymetry was realised by a magnetic field:
http://arxiv.org/abs/physics/0311104
http://arxiv.org/abs/physics/0509111
I had also this idea before and I never saw why it should not work. The interest of the italian paper is that the problem is clearly posed: the charge of the capacitor extracts usable work from heat and that requires entropy decreasing.
Hi exnihiloest,
I have a thread on here about Fu who I have had many coversations with in the past.
As to Prof Germano his device will not work IMO and I have had long debates with him on that subject.
If you want to read why go to fizzx.com and read the topic "isothermal thermionic converters"
Regards
Phil H