Chemical Analysis of the Gallium Surface in a Physiologic Buffer

Gallium and its alloys have been regarded as one ofthe promising materials forflexible bioelectronics due to theirliquid-like mechanical properties, excellent electrical property, andlow toxicity. Although many studies have fabricated bioelectronicsfrom gallium-based liquid metals, gallium surface chemistry inphysiologic conditions is rarely investigated. Here, we investigatedthe chemical change of the gallium surface in a physiologic bufferat 37 degrees C over 45 days. The gallium ion concentration and pHmeasurement indicated thatthe oxidation and corrosionprogressed more rapidly in the physiological buffer than in air.Also, the release of gallium ions and protons followed a square rootof time growth. Various spectroscopic techniques were used tomeasure the chemical composition change on the gallium surface.The FT-IR study indicated that the GaOOH-rich gallium surface produced Ga3+and OH-ions. The XPS study indicated the oxidelayer formation within 5 days, and then the contamination layer was deposited over time, which includes different ions and organicmaterials derived from the physiologic buffer. This study provides a detailed chemical analysis of the gallium surface in aphysiological buffer. These fundamental studies would be a cornerstone for understanding the complex interaction between thegallium surface and the biological environment.

Automated summary

This study investigates the chemical changes on the surface of gallium in a physiological buffer. The results demonstrate that oxidation and corrosion of the gallium surface occur more rapidly in the buffer compared to air. Gallium ions and protons are released following a square root of time growth pattern. Spectroscopic techniques reveal the chemical composition change on the gallium surface. This research provides important insights into the interaction between the gallium surface and the biological environment.