Dr. Michael Dickey, an engineer at North Carolina State University (NCSU), got a grant from the National Science Foundation to experiment in this field with a small team of researchers. That team included NCSU doctoral students, Ju-Hee So, Amit Qusba and Gerard Hayes; NCSU undergraduate student Jacob Thelen; and University of Utah professor Gianluca Lazzi.
The team of researchers made this antennas by injecting an alloy made of the Gallium and Indium into very small channels in a silicone casing. Gallium is a metallic element. Elemental gallium does not occur in nature. it's a liquid at about 86 degrees Fahrenheit. Indium is also metallic but very rare, and melts at a much higher temperature, 315 degrees Fahrenheit. Both are capable of wetting which aids in their adhesion to the form of the silicone casing. The flexible silicone can be shaped into anything, or even as some theorize, stretched to tune the antenna. Dickey explained it to to LiveScience thus.
"The reason this works is that the bulk of it is like water, with low viscosity, but the surface oxidizes and forms a skin, and that skin is what holds it in the channel..."Their research, was recently published as “Reversibly Deformable and Mechanically Tunable Fluidic Antennas,” appeared recently in the Nov. 23 issue of Advanced Functional Materials. this is not the first liquid or at least partly liquid antenna. But it looks like it will be the first one to be commercially viable.
Other liquid antennas:
Ionic Liquid Antenna Concept by N9ZRT - HERE
Liquid Metal Antenna Concept by KD8CIK - HERE