NON-POLARIZABLE DRY ELECTRODE BASED ON NASICON CERAMIC

A NASICON-type ceramic (high sodium ion conductor) is proposed to reco rd bioelectric signals. The electrode does not need gel before its app lication. The principle of the measurements is based on a sodium ion e xchange between the skin and the material. Electrical measurements per formed in saline solutions show that the electrode is slightly polaris able. The skin-electrode impedance was investigated. The impedance dec reases as a function of the time of application. The resistive compone nt is the major source of the impedance change. This can be explained by the perspiration process which occurs immediately with time after t he application of the NASICON-based electrode on the skin. The skin co ndition is also an important parameter. NaCl saline solution or abrasi on causes the resistance to decrease markedly.