Shape-shifting Liquid-Metal Antennas

Researchers devise antennas that can be lengthened—or shortened—to adjust their frequency

Normally, when you want to adjust the resonant frequency of an antenna, you add electronic components like inductors to the circuit. But you can only go so far with that approach; at some point you’ll have to change the physical length of the antenna. That’s fine if you’re designing something, but impractical to do on the fly—until now. Researchers at North Carolina State University in Raleigh used liquid metal to construct an antenna that lengthens or shortens on electronic command.