Bionic fabric can evade infrared cameras

A research team studying bionic intelligent materials in Zhejiang province has developed a type of bionic fiber fabric－an effective heat insulator that can help individuals remain undetectable from most infrared imaging technology.

The research has possible applications in civilian use, industrial production and even by the military, according to the team leader.

It has even been proposed that the material could be used in the design of thermal infrared-stealthy uniforms for soldiers.

"The actual military application may have various and complex conditions, but the fabric's characteristics at least provide a possibility for that," said Bai Hao, professor at Zhejiang University's College of Chemical and Biological Engineering, who led the launch of the research project back in 2016.

Bai explained that the fabric is made from silk, which can be first dissolved in water and then frozen and freeze-dried successively. The team was able to synthesize fibers that were porous, strong and highly thermally insulating.

To demonstrate the fabric's thermal insulation functionality, researchers used it to cover a live rabbit and observed the animal by using infrared imaging equipment. The camera is designed to detect animate objects that radiate heat.

Observations suggested that the animal's body heat was almost invisible to the camera under temperatures ranging from-10 C to 40 C due to the fabric being draped over its body.

"Through investigation, we found the material's average heat conductivity coefficient is lower than that of polar bear hairs, which means the fabric's thermal insulation property is more efficient than polar bear fur," Bai said.

According to Chemical and Engineering News, an academic news website in the United States, the hairs of a polar bear have a hollow core that allows them to reflect back infrared emissions from the animal's body.

This design contributes to minimizing body heat dissipation and keeps the Arctic carnivores warm in their frigid environments.

That is also why scientists discovered that the bears virtually vanish when using infrared cameras. Only the bears' noses, eyes and breath are visible to many highly sensitive, heat-sensing cameras.

The fabric could be applied for many possible uses, Bai said. "Now, we can produce 1 meter of the fabric in just two hours, which is rapid enough for mass production," he said.

"It can be used any place that requires heat retention and insulation, such as in heating pipelines and thermal wear."