https://phys.org/news/2022-09-thermal-m ... power.html
by Bob Yirka , Phys.org
A team of researchers at Nankai University has developed a thermal management multi-layer material that responds to heat or cold by folding or unfolding itself without the need for an external power source. In their paper published in Proceedings of the National Academy of Sciences, the group describes how they came to develop the material and detail its performance when tested.
As scientists around the world work to develop alternative energy sources, others work on ways to use those that have already been developed—solar power, for example, or radiative cooling technologies. In this new effort, the researchers sought a way to shift a device between its use of solar heating or radiative cooling, automatically and without the need for a secondary power source.
For inspiration, the researchers turned to the Himalayan rabbit, which has fur that changes color depending on the season, and the leaves of the Mimosa pudica plant—its leaves open and close in reaction to changes in temperature. Their observations suggested that a material could be made that would behave similarly to the plant, allowing for switching between thermal devices.