Four-electrode measurements on microporous membranes related to dielectric properties of human skin

A new complementary theory on the mechanisms behind the low-frequency permittivity dispersion measured on human skin, is presented. Displacement of counterions in the electrical double layer of the sweat ducts is proposed as a possible source of α-dispersion. Some measurements have been done on pure and modified microporous membranes, using a four-electrode system and a lock-in amplifier. No significant capacitance has been measured so far in these experiments.