Flexible and Compact Animal-Borne Sensors for Ocean Observation

As global environmental changes reshape the underwater biosphere, there is an increasing demand for more comprehensive and biologically relevant measurements to understand evolving conditions. Traditional aquatic measurements are often limited by static, coarse, sparse, and biased sampling methods. Animal-borne sensors offer a potential solution for monitoring marine animals and their physical environments in situ. However, invasive tagging can inevitably impact underwater movement. Here, we introduce a flexible and miniaturized electronic monitoring device designed for free-ranging animals. Our work focusses on the design of the sensing system, emphasizing its compact size, lightweight, flexibility, pressure-tolerance, and extended recording capabilities. The essential components, including sensors, flexible printed circuit boards, and waterproof encapsulation are strictly tested in high-pressure environments. The real-time data sampling is computed and processed on board to alleviate stress on the memory chip. By deploying these tags on animals worldwide, we can address critical data gaps, gain insights into changing ecosystems, and utilize them as active environmental sentinels.