Robotic Dragonfly Changes Color When It Detects Environmental Disasters

DraBot the soft robot flies across bodies of water detecting oil spills and other environmental disasters.
Fabienne Lang

Duke University engineers have developed an electronics-free and autonomous soft robot that is shaped like a dragonfly. Called DraBot, the robot skims across water to signal environmental changes such as rising pH levels, temperature, or oil spills. 

The small 2.2-inch long and 1.4-inch wingspan robot is still in its proof of concept stages but it could prove to be the future environmental mascot we've all been waiting for. 

How DraBot the soft robot works

It's mostly down to air pressure in the robot's wings. DraBot controls the air pressure coming into its wings, where microchannels then move the air into the front wings before it's pushed back through holes and into the back wings. 

When both back wings face down, DraBot remains stationary, but when they're up, it moves forward. 

To further enhance the robot's control, the Duke team added balloon actuators beneath the back wings. When they're inflated, the wings curl upwards, and by controlling which wings move up and down, the team can move DraBot in its desired direction. 

It's clear to see the inspiration for DraBot came from nature, and dragonflies specifically. "Living things don't just move around on their own, they react to their environment," said Vardhman Kumar, lead author of the study. 

This is why the team also added self-healing hydrogel to the flying bot. This is where the real fun comes in.

By adding hydrogel to just one set of wings, the team was able to make DraBot responsive to its environment, specifically changing pH levels in the water.

So when DraBot flies over water that's more acidic, the wings that are covered with the hydrogel fuse together, making DraBot fly around in circles above the area. And when the pH levels return to normal, the self-healing hydrogel infuses the wings, and DraBot flies straight once again.

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This makes it easy for scientists to see the areas with different acidity levels.

Going a step further, the team also included sponges doped with temperature-sensitive material beneath the robot's wings. These sponges soak up water the DraBot skims over, changing color if it picks up oil, and when there's a rise or change in temperature in the water, the sponges turn from red to yellow.

Ultimately, DraBot could become a long-distance autonomous environmental assistant. It could detect oil spills early on, notice where red tide and coral bleaching take place, and much more — assisting scientists in their bid to save the environment and specifically, aquatic life. 

The team's next steps include adding cameras or sensors to DraBot. We can't wait to see these little colorful robots helping environmentalists with their missions.