Copper metamaterial simplifies microwave imaging

Science News : Microwave imaging traditionally uses a single, detector that is moved around to create a full image. By contrast, a new system, created by a team led by John Hunt of Duke University in North Carolina, uses a stationary detector and a thin strip of copper. The researchers created a specialized aperture by etching the copper with a pattern of spirals and loops, which turned it into a metamaterial. The patterning provides very precise control over what frequency of light passes through the aperture. By sending out microwaves of different frequencies, recording the waves that bounce back, and processing that data with a set of algorithms, the imaging system can build a very clear picture of the target with just one-fortieth of the data required by previous imagers. Hunt’s team has tested the technique only on very simple targets, but says that it should be effective in detecting any reflective metals, including wires and pipes in walls or concealed weapons. It could also be adapted for use in security systems to replace bulky video equipment.