Corrosion Resistance and Viability of Radio Frequency Tags under Deep-sea Physicochemical Environments （Japanese Edition）

Abstract

Radio frequency （RF） tags, integrating an aluminum antenna and a silicon IC chip, are widely used for materials management on land, called RF identification （RFID）. They can be also applied to less-common environments, such as volcanoes and the deep sea, where pressure, pH, and hydrogen sulfide concentrations vary from those in ambient air and water. The corrosion resistance of RF tags should be addressed prior to their use in these environments. Here, we examined the corrosion resistance and viability of RF tags under simulated and actual deep-sea conditions. We found that RF tags are resistant to neutral and acidic seawater. However, alkaline seawater, particularly in the presence of sulfides, significantly corrodes the aluminum antenna of RF tags, resulting in loss of functionality. We found that corrosive fluids primarily reach the antenna through the adhesive layers used to construct the layered RF tags. Cladding of the whole tag with polyvinyl chloride sheets prevented corrosion. Our results indicate that well-clad RF tags are viable for deep-sea research, provided the antenna is not in direct contact with highly alkaline or sulfidic hydrothermal vent fluids. This study establishes a foundation for using RF tags in the post-deployment management and identification of marine instruments and marine debris after recovery to the surface.