Modern antennas are made from copper or other metals, but there are limitations to how far they can be bent – and how often – before they break completely. NC State scientists have created antennas using an alloy that “can be bent, stretched, cut and twisted – and will return to its original shape,” says Dr. Michael Dickey, assistant professor of chemical and biomolecular engineering at NC State and co-author of the research.

The antenna consists of liquid metal injected into elastomeric microchannels. The antennas can be deformed (twisted and bent) since the mechanical properties are dictated by the elastomer and not the metal.

The researchers make the new antennas by injecting an alloy made up of the metals gallium and indium, which remains in liquid form at room temperature, into very small channels the width of a human hair. The channels are hollow, like a straw, with openings at either end – but can be any shape. Once the alloy has filled the channel, the surface of the alloy oxidizes, creating a “skin” that holds the alloy in place while allowing it to retain its liquid properties.

“Because the alloy remains a liquid,” Dickey says, “it takes on the mechanical properties of the material encasing it.” For example, the researchers injected the alloy into elastic silicone channels, creating wirelike antennas that are incredibly resilient and that can be manipulated into a variety of shapes. “This flexibility is particularly attractive for antennas because the frequency of an antenna is determined by its shape,” says Dickey. “So you can tune these antennas by stretching them [my italics].”

In his excellent 1942 novella Waldo, Heinlein draws on the idea of broadcast power. The aircars (including the amazing broomstick speedster) use standard, rigid antennas to draw power.

As the story progresses, the deKalb antennas mysteriously fail to function. When one of them is fixed by a "hex doctor", engineers go to investigate.

"What!" put in Stevens. "You don't mean to stand there and tell me an old witch doctor fixed your deKalbs."

"Not witch doctor - hex doctor..."

The skycar looked quite ordinary. Stevens examined the deKalbs and saw some faint chalk marks on their metal sides... "Watch while I cut in reception."

Stevens waited, heard the faint hum as the circuits became activized and looked.

The antennae of the deKalbs, each a rigid pencil or metal, were bending, flexing, writhing like a cluster of worms. They were reaching out, like fingers...
(Read more about Heinlein's broadcast power receptors)

If you haven't read Waldo, treat yourself. Heinlein is a master storyteller; even this early in his career, he created a tour de force story that combined space travel with the classic American supernatural folk tale.