A domestic research team has developed a flexible hydrogel-based thermal regulator that imitates the natural heat regulation of poplar leaves (shown). (iClickArt) Unauthorized reproduction and redistribution of the above photo is prohibited under copyright law.

By Koh Hyunjeong

A domestic research team has developed a material that regulates its own temperature without electricity.

This advanced heating and cooling technology can keep places cool in the summer and warm in the winter without power consumption.

The Korea Advanced Institute of Science and Technology (KAIST) on Nov. 18 announced that the team led by Song Young Min, a professor at KAIST's School of Electrical Engineering, and Kim Dae-Hyeong, a professor at Seoul National University's School of Chemical and Biological Engineering, developed a latent-radiative thermostat (LRT) based on flexible hydrogels that imitates the heat regulation principles of poplar leaves.

Poplars curl their leaves to expose their undersides on hot days to reflect intense sunlight. At night, they prevent cold damage by releasing latent heat from moisture condensed on a leaf's surface.

The newly developed LRT is a thermal control device that alternates on its own between heating and cooling modes.

It switches between four thermal control modes based on the environment including ambient temperature, humidity and light intensity.

The device also switches between heating and cooling modes autonomously without consuming electricity based on the surrounding environment.

Outdoor experiments showed that the LRT maintained temperatures up to 3.7 degrees Celsius lower in summer and a maximum of 3.5 degrees higher in winter.

Song said, "This study is significant in presenting a thermal management device that adapts to seasonal and climate changes by engineering a reenactment of nature's intelligent thermal regulation strategy."

The study was published on Nov. 4 in the international academic journal Advanced Materials.

hjkoh@korea.kr