Seawater Antenna

In some ways this is similar to the liquid antenna I wrote about in May. [post here] But that antenna was encased in flexible silicone rubber, with a conductive liquid metal inside. There are patents out there for Ionic water antennas. These uniformly fill tubes or hoses with salt water. This antenna is literally just made of water, and uses no casing or enclosure of any kind.

Your tap water is probably not a good conductor of electricity. If it is, it's probably not safe to drink. By comparison, salt water (saline) is pretty conductive. The difference is pretty clear one has sale (Sodium Chloride- NaCl) one does not. But at the atomic level there is a more specific reason. Electrical current is transported by the ions in the saline solution. salt increases both the density and conductivity of water. Seawater is about 3% salt, but it also contains Magnesium (Mg), Calcium (Ca), Potassium (K), Chlorine (Cl), and Sulphate (SO4); of thoseat least Magnesium also improves conductivity.

Conductivity is defined as the ratio of current density to the magnitude of the electric field. That's measured as Siemens per meter. Silver, Gold and Copper are all metals and all very conductive. Let's put that in perspective:
Silver = 6.30 × 10⁶ S/m
Copper =  5.69 × 10⁷ S/m
Gold = 4.52 × 10⁷ S/m
Aluminum = 3.5 × 10⁷ S/m
Water = 10 × 10^-6 S/m
Saline = 4.8 S/m

As you can see in the video, it uses a pump to first pull water up to a probe. That "probe" applies current, and shoots a stream of sea water vertically to act as it's antenna. The height of the stream is determined by water pressure, which in turn determines frequency. It makes the antenna completely configurable, so in a marine scenario one might only need one all-purpose seawater antenna for any situation.

A liquid antenna

Its no metaphor. This is a liquid antenna. Traditional antennas are made from metal poles or metal wire, usually copper. They have their upsides and downsides, but small antennas in modern portable electronics they are more exposed to handling and thus to breakage than their full-scale cousins. But it appears we have a solution.

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