Illusion cloaks that make one object look like another are a fascinating type of invisibility device. The general idea is that such a device would make an apple look like a banana or a fighter plane look like an airliner. Clearly this would have important applications.
But while materials scientists have made great strides in building ordinary invisibility cloaks that work in the microwave, infrared and optical parts of the spectrum, making illusion cloaks is much harder. That’s because the bespoke materials they rely on require manufacturing techniques that seem like a distant dream. ….Full Article Source