Scientists from Tampere University in Finland have developed a robot measuring 0.2 inches (4 mm) that uses wind and light energy to fly. The "flying aerial robot powered by light-responsive materials" - FAIRY - weighs only about 1.2 milligrams, which means it can be blown away by even a gentle breeze. It resembles dandelion seeds, with ultra-fine bristles emerging from wings that flutter gently when activated by light. Due to the distance between the bristles of the capsule, a vortex of air or "vortex ring" is produced during its flight, increasing its lift. This lift allows it to remain stable when wind blows at it, and a similar vortex ring is created in the direction of FAIRY's flight once it takes off. However, when light is directed at the robot, it can cause its wings to open or bend, changing the shape of the vortex. This property can be used to control its takeoff and landing. Researcher Hao Zeng said, "This artificial seed outperforms its natural counterparts and is equipped with a soft actuator." An actuator is a device that converts energy inputs, such as light or electricity, into kinetic energy. Zeng noted that "the actuator is made of light-responsive liquid crystal rubber, which stimulates the opening or closing of the bristles when excited by visible light."
In recent years, many research groups around the world have created miniature robots from "soft" polymers that respond to external stimuli. These include "fish" that swim, drug delivery robots, and flying bees and flies—all of which move when light is shone on them. The field of soft robotics is based on the idea of using more flexible materials to attempt to create robots resembling natural forms, such as cheetahs. This would make them more dynamic and better able to move across a variety of terrains. In their study published in the journal Advanced Science, engineers looked to the humble dandelion for inspiration for a new flying robot. Zeng stated, "The robot can be powered and controlled by a light source, such as a laser beam or LED." Researchers hope to improve the robot's sensitivity so it can be operated by sunlight. They will also expand its size to about 4 inches (10 cm) so it can carry small electronic devices, such as GPS receivers or chemical sensors.
