By Stephen Beech
A new environmentally friendly water robot consists of fish feed.
The edible machine uses biodegradable fuel and surface tensions to advise the water surface.
It creates a safe and nutritious alternative to environmental monitoring devices from artificial polymers and electronics, say Swiss scientists.
They explained that the boot-shaped robot exploits the same phenomenon-the Marangoni effect, which is used by some water insects to drive over the water surface.
A chemical reaction in a tiny removable chamber creates carbon dioxide gas, which in turn is reached a fuel channel and the fuel is shown.
The sudden reduction in the water surface tension caused by the selected fuel then drives the robot.
This clever design is not only effective, which enables robots to move freely on the surface of the water for a few minutes, but also completely non -toxic and biodegradable.
The Swiss team said that the components of the triggering chemical reaction – citric acid and sodium bicarbonate – are the same that are used in a typical school science experiment with a volcano.
And the “fuel” is propylene glycol – a liquid that often occurs in skin care products.
Shuhang Zhang from the Swiss Federal Federal Institute of Lausanne (EPFL) said: “While the development of miniature swimming robots for natural environments continued quickly, they typically rely on plastic, batteries and other electronics that present the challenges for use in sensitive ecosystem.
“In this work we show how these materials can be replaced by completely biodegradable and edible components.”
He says that the robot, which is described in the magazine Nature Communications, is not only harmless to aquatic fauna, but also advantageous.
In order to give the external structure, which is about five centimeters long, the strength and stiffness, the research team used fish feed with a 30% higher protein content and 8% lower fat content than commercial pellets.
The doctoral student, Mr. Zhang, said: “At the end of its life, the device can serve as food for aquatic wild animals, just like the animals.”
The EPFL team imagines that the robots are used in large numbers.
They say that each device with biodegradable sensors for collecting environmental data such as water acid, temperature, pollutants and the presence of microorganisms would be equipped, which could be read after the collection or after remote sensing.
Instead of precisely checking the directional movement of the robots, the team has produced the variants “turn left” and “right rotation” by changing the asymmetrical design of the fuel channel.
The control level is everything that is needed to dispel the robots over the water surface, and your pseudo-random movements are based on insects, which means that they make ideal vessels for the provision of nutrients or medication.
The team leader Professor Dario Floreano from the EPFL -School of Engineering added: “The replacement of electronic waste by biodegradable materials is the subject of an intensive study, but edible materials with targeted nutritional profiles and functions have hardly been considered and opened a world full of opportunities for the health of humans and animals.”