On march 25th, 2021 engineers at Duke University developed an electronic free, soft robot that looked like a dragonfly and could skim across water and react to its environmental conditions such as pH, temperature or even the presence of oil.

The popularity of soft robots has recently grown in the field of robotics, specifically due to their ability of handling small delicate objects and reaching tight spaces because of having really soft bodies.

The robot uses a prototype material made by Shyni Varghese, Processor of Biomedical Engineering, Mechanical Engineering and Material Science and Orthopedics. The material is called “Self healing hydro-gel”, which can react to changes in pH. A change in the pH causes the Hydro-gel to form new bonds that are reversible when pH returns to its original level.

The robot works by controlling the air pressure coming in its wings to help it propel through the surface of water.

To boost the robot’s environmental awareness, researchers fitted it with temperature-responsive materials, so that when the robot skims over water with oil on the surface, the sponges on its body soak it and change to a corresponding color for indication. Additionally, if the water is warm the wings on the robot will change color from red to yellow.

Even if it's a small invention, the researchers believe that it can play an important role as an environmental robotic sensor in the future. Responsiveness to pH can help in detecting serious problems like acidifying of freshwater and it's color changing ability can help in early detection of oil spills and also based on the temperature, it can help in spotting signs of bleaching in coral reefs.

Shyni Varghese has visions of using some sort of synthetic biology that generates energy to power the robot’s flight, instead of air pressure.

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