Actually part of those issues result from the need for ultra-smooth bottom electrodes to achieve optimal substrate (contact) coverage, which necessitates minimizing surface roughness, as even minor imperfections can disrupt the uniformity of the assembled protein layer. Still, even with optimally packed protein monolayers, interstitial voids are unavoidable because of the shapes of these biomolecules. Voids expose the underlying substrate, creating pathways for electrical leakage and even short-circuits.