We live in a time of exciting technological developments, and the development of smart materials has become of great interest, giving rise to soft and flexible stimuli-sensitive materials that are being employed for the fabrication of small robots that can be operated wirelessly. And in this field of smart materials, a team of scientists has developed a soft-bodied robot inspired by the dandelion seed that is able to fly with the wind and be controlled by light.
Scientists develop an artificial dandelion controlled by light. Source: @emiliomoron, the image of the dandelion is in the public domain.
When we talk about smart materials, we refer to a group of synthetic materials with the ability to deform in a programmed and reversible way in response to external stimuli, such as heat, humidity, magnetic fields or light.
Although scientists discovered some time ago how to make stimuli-responsive polymer-based smart materials move and even swim, no one had reported that they could make them fly, as it requires a perfect combination of several factors, such as lightness, actuator performance and aerodynamics, which makes making them fly, or even glide, a big challenge.
But researchers from the University of Tampere's Light Robots group are dedicated to flying smart materials, and have developed a porous structure based on soft matter capable of dispersing with the help of the wind and taking off and landing under the control of a beam of light. Their design was inspired by the dandelion seed, and consists of 54 pieces of filament bristling centro-symmetrically around a rectangular soft actuating film, and has several features that mimic the natural seed, including the way they are dispersed by wind. But unlike the natural seed, this artificial seed is made of a light-sensitive liquid elastomer polymer that produces an opening and closing effect of its bristles when excited with visible light.
Schematics of the fabrication process of dandelion-inspired disperser. Source: image elaborated in powerpoint.
This polymer action allows light to be used to change the shape of the dandelion seed-like structure, manually adapting it to suit the wind speed and direction, allowing it to perform wind-assisted takeoffs and landings controlled by a beam of light.
Schematic of geometries. Source: image elaborated in powerpoint.
Currently, making a small-scale object fly requires a very high performance of the actuator materials, and although various materials have been used for this purpose, such as piezoelectric actuators or dielectric elastomers, which have a high power density, the problem is that they require an electrical cable connection for power.
But thanks to the results obtained by this team of scientists, novel approaches for wirelessly controlled micro- and nano-robots that can fly using the wind over a large airspace can be envisioned.
For example, the researchers will focus on improving the sensitivity of the material so that the artificial dandelion seed can be operated in sunlight, and improve its structure so that it can carry a sensor or chemical, so the research is an important step towards the development of pollinator devices.
And although it sounds like science fiction, in the future there could be tiny intelligent devices scattered in the wind carrying pollen, being directed by light to a specific place, which would have a great impact on agriculture. But there is still a long way to go, scientists still face the challenge of making the devices land accurately and control multiple robots over long distances, and they must find a way to make them biodegradable.
But it is certainly an interesting application, since many pollinating insects are facing extinction due to global warming, not that we should think about replacing them, but it is better to have a plan B while reversing the effects of global warming.
Well friends, I hope you liked the information, see you next time!
References
Jianfeng Yang, Hang Zhang, Alex Berdin, Wenqi Hu, Hao Zeng. Dandelion-Inspired, Wind-Dispersed Polymer-Assembly Controlled by Light; Advanced Science, December 2022
