In 2012, a team at Duke University in the United States created a self-healing hydrogel. Researchers hope to use this hydrogel to create a soft robot. After several iterations, the researchers decided to shape the robot into a dragonfly shape with a micro-channel network inside, and use air pressure to control it through a micro-pipe connected to the outside.
Recently, this "robotic dragonfly"-DraBot was born, which can "fly" with its wings on the water. Utilizing the characteristics of hydrogel, DraBot can make corresponding changes according to the DH value of the surrounding water. If the water becomes acidic, the front wing on one side merges with the back wing, and the imbalance makes the robot no longer move in a straight line, but will turn in circles. Once the DH returns to its normal level, the hydrogel will "return to its original shape" and the fused wings will separate and return to linear motion. The researchers also incorporated temperature-sensitive materials into the wings. When the water became too hot, DraBot's wings changed from red to yellow. Researchers believe that this measurement may play an important role in environmental robot sensors in the future.