Dry Textile Electrodes for Wearable Bio-Impedance Analyzers

In this paper the results of the study performed on dry textile electrodes for bio-impedance measurements are reported. The use of two different conductive fabrics is investigated: a silver-plated bi-elastic knitted fabric and a bi-layer structure comprising a layer of a silver-plated knitted fabric and a layer of conductive silicone. In this latter, the presence of the silicone layer guarantees a good contact with the skin, which is a fundamental condition for accurate bio-impedance measurements, and preserves the silver by oxidation due to sweat. The fabricated textile electrodes have been sewn on elastic cuffs and two different relative positions of the current and voltage electrodes have been investigated. The proposed cuffs are suitable to be embedded into a t-shirt for continuous and real-time bio-impedance measurements. The reliability of the developed prototypes is validated by comparison with data obtained from Ag/AgCl commercial electrodes. Promising results have been obtained for both the investigated conductive fabrics.