We report a biomimetic polyelectrolyte based on amphiphilic polymer nanosheet multilayer films. Copolymers of poly(N-dodecylacrylamide-co-vinylphosphonic acid) [p(DDA/VPA)] form a uniform monolayer at the air-water interface. By depositing such monolayers onto solid substrates using the Langmuir-Blodgett (LB) method, multilayer lamellae films with a structure similar to a bilayer membrane were fabricated. The proton conductivity at the hydrophilic interlayer of the lamellar multilayer films was studied by impedance spectroscopy under temperature- and humidity- controlled conditions. At 60 degrees C and 98% relative humidity (RH), the conductivity increased with increasing mole fraction of VPA (n) up to 3.2 X 10(-2) S cm(-1) for n = 0.41. For a film with n = 0.45, the conductivity decreased to 2.2 X 10(-2)S cm(-1 )despite the increase of proton sources. The reason for this decrease was evaluated by studying the effect of the distance between the VPAs ((lvpA) ) on the proton conductivity as well as their activation energy. We propose that for n = 0.41, (lvpA) is the optimal distance not only to form an efficient two-dimensional (2D) hydrogen bonding network but also to reorient water and VPA. For n = 0.45, on the other hand, the l(vpA) was too close for a reorientation. Therefore, we concluded that there should be an optimal distance to obtain high proton conductivity at the hydrophilic interlayer of such multilayer films.