We show that the addition of a topological invariant (Gauss-Bonnet term) to the anti-de Sitter (AdS) gravity action in four dimensions recovers the standard regularization given by holographic renormalization procedure.
   This crucial step makes possible the inclusion of an odd parity invariant (Pontryagin term) whose coupling is fixed by demanding an asymptotic (anti)self-dual condition on the Weyl tensor. This argument provides a simple derivation of the holographic stress tensor/Cotton tensor duality observed in recent literature in solitonic solutions and hydrodynamic  models.
   A general prescription to generate the counterterm series for AdS gravity in any even dimension from the corresponding Euler term is also briefly discussed.

It was in early 1954 when the Soviet Scientist Feodor Vholkensthein formulated the first quantum physical description of adsorption processes on semiconducting surfaces. During his studies he postulated an electric field control of electronic surface states and named this the "electroadsorptive effect". The theory, however, was neglected for decades because of the Babylonian problem: Languages and ideologies: Soviet and US, Theoretical and Applied Physics- In the 90's many working groups in the field of MEMS chemical sensors reported results that were exactly the electroadsorptive effect and
this initiated a revival of the models developed long ago. That's the good part of the story.
The bad thing about the story is that engineers dare to use the effect for various applications! The talk will summarize results, touch on theory, present possible applications and discuss the present state of    advances and analytical/modelling challenges one has still to overcome.