Chinese researchers make “raincoat” for electromagnetic shield
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 (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 electromagnetic interference and pollution. But on outdoor electronic equipment, such as signal stations, the shields can be corroded by sewage pollution and acid rain, and the shielding effectiveness reduced. What was needed was the “lotus effect.” This refers to the self-cleaning of the lotus leaves. When water hits the rough surface of the leaf, the droplet rebounds as a ball, rolling off and taking away dirt particles on the surface. Butterfly wings, rose petals, and some insects also have surfaces with such properties.