Thanks to their large wings, maple seeds float through the air in autumn and spread far into the surrounding area thanks to their rotating movement. Researchers from Tampere University in Finland and the University of Pittsburgh in the USA have now taken advantage of this fact: The team led by Hao Zeng and Jianfeng Yang developed small robots that imitate the flight behavior of maple seeds.
In contrast to their stiff metal counterparts, the newly developed flying robots are made of flexible, soft materials. The two researchers presented a first seed-like mini-robot at the beginning of 2023. This technology is based on liquid-crystalline polymers based on azobenzene, which deform when exposed to light. These complex material compounds make it possible to control the small aircraft using light through photochemical reactions.
The secret lies in the shape of the wings: when light of a certain wavelength falls on the elastic structures, the shape of the wings changes so that the device rises, falls or changes its rotation speed. The artificial maple seeds achieve their general lift in a similar way to helicopters by creating an upward suction through their own rotation.
“The robots are designed to be released into the atmosphere and then to enter passive flight using the surrounding wind currents. Equipped with GPS and other sensors, they can provide real-time monitoring of the local environment, including by measuring pH levels,” says Yang. For example, it is conceivable that the flying helpers could be used to research endangered species or dropped over inaccessible areas such as deserts or canyons to collect information and take small soil samples. They could also play a key role in the search for and rescue of missing people in the future.