Liquid-Metal Antennas Lengthen or Shorten on Electronic Command

A significant drawback slowing the advance of liquid metal electronics devices is that they tend to require external pumps that can't be easily integrated into electronic systems. A team of North Carolina State University researchers set out to create a reconfigurable liquid metal antenna controlled by voltage only. They did so by using electrochemical reactions to shorten and elongate a filament of liquid metal and change the antenna's operating frequency. Applying a small positive voltage causes the metal to flow into a capillary, while applying a small negative voltage makes the metal withdraw from the capillary. Although antenna properties can be reconfigured to some extent by using solid conductors with electronic switches, the liquid metal approach greatly increases the range over which the antenna's operating frequency can be tuned. Many potential applications await within the realm of mobile devices.