Electrode design, polymer electricity

There are several things that need to be pointed out on this design. First, the upper electrode is porous, either because it is very thin (10-20 nm) or because it is deposited under such conditions that it cracks. In any case, the polymer beneath it comes into contact with the gas or vapor. Obviously, it is difficult to make robust electrical connections to the top electrode. Fortunately, it is not necessary because it forms an electrically floating plate, which is common to the two capacitors one between the Cr, Ni, Au plate (Ci) and the other between the top and the Ta plate (C2). The corresponding leakage resistances are R and R2. The response of this sensor to water vapor is shown in Fig. 8.14. 

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