This Zebra-Inspired Stripey, Stretchy "Radiation Modulator" Could Be a Big Win for Sustainability

Scientists at Korea University, the Gwangju Institute of Science and Technology (GIST), and Pusan National University, have taken a step towards sustainability for electronics with a biodegradeable radiation modulator capable of minimizing wasted energy — inspired by zebra stripes.

"Recent advances in passive radiative cooling systems describe a variety of strategies to enhance cooling efficiency, while the integration of such technology with a bioinspired design using biodegradable materials can offer a research opportunity to generate energy in a sustainable manner, favorable for the temperature/climate system of the planet," the research team explains. "Here, we introduce stretchable and eco-resorbable radiative cooling/heating systems engineered with zebra stripe–like patterns that enable the generation of a large in-plane temperature gradient for thermoelectric generation."

In the paper, brought to our attention by IEEE Spectrum, the team describes a novel design of flexible thermoelectric generator (TEG) in which hot and cold regions are placed side-by-side, rather than stacked, on a caprolactone sheet — looking from the outside like the black and white stripes of a zebra. The difference in temperature between the hot and cold regions is what generates electricity — with testing showing enough of a differential between the stripes to generate roughly 6µW per square meter, a small amount but enough for low-powered sensor systems.

The performance of the device as-is, though, is only part of the team's work. The soft material is flexible, retaining its energy generating capabilities after repeated stretching and relaxing, and easily disposed of when no longer required: just drop it into a salt water solution and the entire device degrades into non-toxic by-products in a little over a month.

The team's work is available under open-access terms in the journal Science Advances.