Is thermo-ionic emission at room temperature exploitable?

Abstract

In this brief note we describe two devices, a sort of flat and spherical capacitor, with which one should be able to test the possibility of creating a macroscopic voltage, and thus exploitable current, out of a single thermal source at room temperature. The basic idea is trivial and it makes use of a thermo-emitting cathode with work function as low as 0.7eV. The idea is not completely new, but our approach is simpler and neat. When implemented, it should allow to assess if approaches based on thermo-ionic materials at room temperature really violate the Second Law of Thermodynamics macroscopically.