Scientists create edible robot that monitors water and feeds fish

By Dean Murray

Researchers have made a robot that can be eaten after use.

The eco-friendly aquatic bot is made from fish food and could be used to monitor the environment and deliver nutrients.

It works by creating a chemical reaction within a tiny detachable chamber that pushes out carbon dioxide gas to propel it along.

The boat-shaped robot has been developed by scientists at the EPFL research university in Switzerland.

It takes advantage of the same phenomenon – the Marangoni effect – used by some aquatic insects to propel themselves across the surface of water. Once its tasks are done, it can be eaten by fish.

EPFL PhD student Shuhang Zhang said: "While the development of miniature swimming robots for natural environments has progressed rapidly, these typically rely on plastics, batteries, and other electronics, which pose challenges for mass deployment in sensitive ecosystems.

"In this work, we show how those materials can be replaced by completely biodegradable and edible components."

The EPFL team envisions the robots could be deployed in large numbers. Each device would be equipped with biodegradable sensors for collecting environmental data like water pH, temperature, pollutants, and the presence of microorganisms, which could be read out after collection or by remote sensing.

Shuhang Zhang and a team from the Laboratory of Intelligent Systems, led by Dario Floreano in the School of Engineering, have recently reported the work in Nature Communications.

“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,” Floreano said.