Resumen de Invisibility cloak could hide mice from snakes
A team at Zhejiang University in Hangzhou, China, has taken a significant step forward by making a cloak for infrared radiation, whose wavelengths are only just too long to see. All animals--including humans--emit infrared as heat. Snakes can sense this radiation even in darkness, using it to hunt down their prey. "They want to simulate the scene of catching a mouse," says team member Hongsheng Chen. His team did that by getting a snake's-eye view of a toy mouse heated to 35°C through a thermal camera. They built an accordion-like structure from germanium, leaving a 2.7-centimeter-wide cavity in the middle for the toy mouse. The germanium sent infrared rays from behind the mouse on a curved path around the cavity then bent them back into straight lines for the camera making it seem like they had traveled through the structure. Rays emitted from inside the cavity were blocked. The team tested it by hiding the lower body of the toy mouse from the camera--its head seemed to float in the air. They also showed that the cloak could work as the environment around the toy varied between 30°C and 45°C.
