Infrared cameras are the heat-sensing eyes that help drones find their targets even in the dead of night or through heavy fog. Hiding from such detectors could become much easier, thanks to a new cloaking material that renders objects — and people — practically invisible. “What we have shown is an ultrathin stealth ‘sheet.’ Right…
Standing May Help Improve Antennas That Scan in All Directions
Antennas often need to trace circles in the sky. For example, radar arrays atop air-traffic control towers rotate to sweep signals in all directions. But spinning large objects nonstop takes a lot of time and mechanical energy. So scanning from a stationary position could speed up long-range detection and communications. Now, with support from a…
Antenna Design Turns Vehicles into Broadcasting Equipment
High-frequency antennas transmit radio waves across vast distances and even over mountain ranges using very little energy, making them ideal for military communications. These devices, however, have one big problem: They need to be huge to operate efficiently. Instead of adding more bulk, University of Wisconsin–Madison engineers are working to increase the effective size of…
Better Battery Imaging Paves Way for Renewable Energy Future
In a move that could improve the energy storage of everything from portable electronics to electric microgrids, University of Wisconsin-Madison and Brookhaven National Laboratory researchers have developed a novel X-ray imaging technique to visualize and study the electrochemical reactions in lithium-ion rechargeable batteries containing a new type of material, iron fluoride. “Iron fluoride has the…