  Direct and alternating current iontophoresis and electro-osmosis
methodologies have provided new methods of transcutaneous drug delivery. A
byproduct of such methods is lowering the electrical impedance of the electrode
to skin contact, as conductive ions permeate the stratum corneum, the primary
resistive layer of the skin. We developed a method for adapting iontophoresis
to condition the electrode to skin contact, both for electrophysiological
recording and electrical stimulation of body tissues. By utilizing direct
current to treat electrodes with high impedance we show the effectiveness of
iontopheresis as a driving force for permeation of ionic electrolyte into the
skin barrier. We applied direct current (DC) levels of 50 {\mu}A to electrodes
on the human head for 30 seconds with paste (Nihon Kohden Elefix) electrolyte.
Typically immediately after DC treatment conditioning there was an impedance
drop of 10-30%. The effect was lasting over several hours, with the paste
electrolyte. These results demonstrate the feasibility of DC conditioning to
reduce the set time of electrolytic solutions and to maintain good skin contact
during extended recording or stimulation sessions.
