The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase II project is to reduce the serious and sometimes fatal injuries caused by accidental ingestion of coin cell batteries, particularly in children. From 2010 to 2019, over 70,000 battery-related emergency room visits were recorded in the United States, with some resulting in internal burns, surgeries, or death. This project aims to develop safer battery casings that passively deactivate upon exposure to bodily fluids, reducing the risk of electrochemical injury. By providing a built-in safety mechanism that requires no external electronics or internal design changes, this innovation enables battery manufacturers to adopt enhanced safety standards with minimal production disruption. In addition to protecting children, the same technology could be extended to battery-powered ingestible and implantable medical devices, offering a broader benefit to public health. The work also advances scientific understanding of environmentally responsive materials and their integration into real-world consumer products. This Small Business Innovation Research (SBIR) Phase II project focuses on addressing the technical challenge of preventing current-induced tissue damage when coin cell batteries contact wet environments. The innovation lies in the use of metals that exhibit distinct electrochemical properties depending on environmental conductive fluids. The research will optimize the composition, thickness,