The Edible Aquatic Robot is a groundbreaking innovation developed by EPFL scientists, who have successfully created a biodegradable and non-toxic device to monitor waterways. This remarkable invention leverages the Marangoni effect, which allows aquatic insects to propel themselves across the surface of water, to create a safe and efficient alternative to traditional environmental monitoring devices made from artificial polymers and electronics.

The robot’s clever design takes advantage of a chemical reaction within a tiny detachable chamber that produces carbon dioxide gas. This gas enters a fuel channel, forcing the fuel out and creating a sudden reduction in water surface tension that propels the robot forward. The device can move freely around the surface of the water for several minutes, making it an ideal solution for monitoring waterways.

What makes this invention even more remarkable is its edible nature. The robot’s outer structure is made from fish food with a 30% higher protein content and 8% lower fat content than commercial pellets. This not only provides strength and rigidity to the device but also acts as nourishment for aquatic wildlife at the end of its lifetime.

The EPFL team envisions deploying these robots in large numbers, each equipped with biodegradable sensors to collect environmental data such as water pH, temperature, pollutants, and microorganisms. The researchers have even fabricated ‘left turning’ and ‘right turning’ variants by altering the fuel channel’s asymmetric design, allowing them to disperse the robots across the water’s surface.

This work is part of a larger innovation in edible robotics, with the Laboratory of Intelligent Systems publishing several papers on edible devices, including edible soft actuators as food manipulators and pet food, fluidic circuits for edible computation, and edible conductive ink for monitoring crop growth. The potential applications of these devices are vast, from stimulating cognitive development in aquatic pets to delivering nutrients or medication to fish.

As EPFL PhD student Shuhang Zhang notes, “The replacement of electronic waste with biodegradable materials is the subject of intensive study, but edible materials with targeted nutritional profiles and function have barely been considered, and open up a world of opportunities for human and animal health.” This groundbreaking innovation in edible aquatic robots has the potential to revolutionize the way we monitor waterways and promote sustainable development.

Scientists have developed an innovative tool to revolutionize ocean conservation efforts. The Migratory Connectivity in the Ocean (MiCO) database, created by researchers from The University of Queensland and Duke University, provides a comprehensive global map of marine migratory patterns. This groundbreaking interactive tool aims to bridge information gaps for policymakers and conservationists, ultimately protecting at-risk wildlife.

Dr. Lily Bentley, from UQ’s Centre for Biodiversity and Conservation Science, explained that the online tool offers a freely accessible global view of marine migratory connectivity. “MiCO brings together thousands of records from over 1,300 sources to map how marine animals traverse the world’s oceans,” she said. The database covers 109 species, including birds, mammals, turtles, and fish.

Researchers discovered that many marine animals migrate through national waters and the high seas during their life cycles, exposing them to various threats across countries. Dr. Bentley highlighted the importance of cross-boundary cooperation in protecting these migratory species. “MiCO enables scientists, governments, and international organisations to understand how migratory marine species link regions and jurisdictions,” she said.

The intricate connectivity described in the system underscores the need for globally-aligned conservation efforts. Associate Professor Daniel Dunn, Centre director, emphasized that no country can fully protect migratory species on its own. “To protect these species effectively, nations must work together,” he said.

MiCO’s freely available models have already been identified as a valuable asset to inform the implementation of the recent High Seas Treaty, which seeks to safeguard biodiversity beyond national waters. The system also aligns with the Convention on Migratory Species’ goal of developing a global atlas of animal migration, an effort to which MiCO seeks to be a key contributor.

Researchers say more than two-thirds of marine migratory species are still unassessed and future expansions of MiCO are planned. Their ultimate goal is to provide the most comprehensive global baseline of connectivity generated by marine migratory species possible, so that conservation strategies are based on robust data. This research has been published in Nature Communications.

The study, published in Nature Cities, reveals that all 28 most populous U.S. cities are experiencing some degree of land movement, with the majority sinking at varying rates due to a combination of factors including groundwater extraction, climate change, and human activities such as construction and urbanization.

Lead author Leonard Ohenhen, a postdoctoral researcher at Columbia Climate School’s Lamont-Doherty Earth Observatory, notes that as cities continue to grow, subsidence can become more pronounced, producing stresses on infrastructure that may exceed safety limits. “We will see more cities expand into subsiding regions,” he says.

The study uses satellite data to map land movements in the 28 cities, including Houston, which is experiencing some of the most rapid sinking, with over 40% of its area subsiding more than 5 millimeters per year. Other Texas cities, Fort Worth and Dallas, are also among the fastest-sinking, while areas around New York’s LaGuardia Airport and parts of Las Vegas, Washington, D.C., and San Francisco are experiencing localized fast-sinking zones.

Researchers found that groundwater removal for human use was responsible for 80% of overall sinkage, with compaction below ground level causing subsidence at the surface. Climate-induced droughts in some areas will likely worsen subsidence in the future, says Ohenhen.

The study also reveals that natural forces are at work in some areas, such as the weight of ancient ice sheets that once covered much of interior North America. Even today, some cities like New York, Indianapolis, Nashville, Philadelphia, Denver, Chicago, and Portland are still subsiding due to these bulges, with rates ranging from 1 to 3 millimeters per year.

The researchers emphasize that continued population growth and water usage will likely exacerbate subsidence in the future. They recommend that cities focus on solutions such as land raising, enhanced drainage systems, and green infrastructure to mitigate flooding, and retrofitting existing structures to address tilting hazards.

Ohenhen concludes, “We have to move to solutions.” The study was coauthored by researchers from various institutions and provides a valuable resource for policymakers and urban planners to address the challenges posed by subsidence in major American cities.