The ‘lotus effect’ to shield against EMI

ONE of the fascinations of the lotus is that it grows in mud, but is always clean. Chinese researchers were inspired by the flower to develop a new, self-cleaning electromagnetic shielding material.

Extensive applications of electronic devices make electromagnetic interference, or EMI, a serious problem, harming human health, equipment, and the environment. In 1969, the United Nations listed electromagnetic pollution as a major environmental pollution.

Most EMI shielding materials, made of metal, can isolate electronic devices from their surroundings, restraining EMI and pollution. But on outdoor equipment, such as signal stations, the shields can be corroded by sewage pollution and acid rain, reducing the effectiveness of the shield.

What was needed was the “lotus effect.”

This refers to the self-cleaning by lotus leaves. When water hits the rough surface of the leaf, the droplet rebounds as a ball, rolling off and taking away surface dirt particles.

Butterfly wings, rose petals, and some insects also have surfaces with such properties.

Researchers from the Chinese Academy of Sciences developed a material with effective EMI shielding and a self-cleaning surface using chemical composites.

Their research, led by Zhang Wenge, was published in the international journal Composites Science and Technology.