With its ridiculous weight of 1,2 milligrams, FAIRY (Flying Aero-robots based on Light Responsive Materials Assembly), is the smallest "soft" flying micro robot that responds to light.
A cybernetic dandelion
You say "soft robotics" and it is as if you said "biomimicry": the best inspiration for building these "soft" devices has always come from nature. Once again: the researchers were inspired by dandelion seeds.
Just like them, the FAIRY micro robot could fly in the form of a dandelion, pushed by the wind and controlled by light: perhaps to support the pollination of bees, threatened by pollution e diseases.
How does the FAIRY micro robot work?
'FAIRY can be operated and powered by light sources such as laser beams or LEDs,' says Prof. Hao Zeng, an expert in micro robots from the University of Tampere in Finland. The findings included in his research published in Advanced Science (I link it to you here) show that the micro robot can represent a significant step towards practical use.
FAIRY is light because it is designed with a "porous" design, which helps it take flight. Its shape similar to that of a dandelion seed allows the micro robot to fly even for long distances (and in difficult conditions) without the need for further assistance.
It is not flyable like a drone but its shape can be changed to match the wind, just like a ship's sail.

How it's done?
FAIRY's structure is quite simple: it is composed of a filament made up of fibers measuring only 14 microns thick. These "bristles" are connected by an actuator, a light-controlled flexible strip, which manages the opening and closing of the micro robot.
According to Zeng, this "artificial seed" is superior to its natural counterparts precisely by virtue of this soft actuator. FAIRY's "rudder" is made of a liquid crystalline elastomer that responds to visible light, causing the bristles to open or close.
FAIRY micro robots: the next steps
Zeng and his team tested the artificial "seeds" in wind tunnels and under laser lights, imagining flying millions of them carrying the pollen through the air, with the light guiding them towards the target. There is still quite a bit of work to be done before this can become a reality.
There are currently two problems: the precision of the remote control and above all the biodegradability: if these synthetic "dandelions" do not dissolve after use, the road from saving to ecological disaster is short.
The researchers gave themselves 5 years to solve the problem: the project, which started in September 2021, will continue until August 2026.