Abstract

The resistivity ρ(PEM) of polyelectrolyte multilayers (PEMs), PEI(PSS/PAH)(24), PEI(PGA/PAH)(12), PEI(HA/PLL)(12) and PEI(PSS/PLL)(12), in a free-hanging configuration was estimated combining electrochemical impedance spectroscopy (EIS) and atomic force microscopic (AFM) images. Surprisingly, the obtained value of several kΩcm is at least 6 orders of magnitude lower than that reported previously, where the resistivity was determined in the conventional PEM-on-electrode system. The significant discrepancy indicates the unexpectedly low electrical PEM resistance in the absence of redox-active ions and the sensitivity limitation in the conventional system.