Since years, our mobile phones are no longer sporting those ugly extendable antennas, that needed to be spread out each time you answered the phone, and that had a hard (and often short) life. Nowadays, antennas are concealed within the casing of our phones, and soon we might see, in this field as well as in others, liquid metal flexible antennas.
Those flexible antennas, manufactured with an alloy of indium and gallium which stays in a liquid state, are the subject of a North Carolina State University research.
The alloy is injected inside extremely thin channels, the size of a hair. Once it is in, it forms some sort of skin which holds the alloy in place and allows it to remain liquid.
Thanks to this, antennas are extremely flexible, and since an antenna’s frequency is influenced by its shape, shortening or lengthening them means changing their receiving properties according to one’s need. Along with this feature, which makes it useful for devices already on the market, its high durability makes it ideal for applications where sturdiness is a must, for example in the military field or to monitor the condition of civilian installations such as skyscrapers or bridges.
For example, as we know, bridges stretch and expand with wind, temperature changes or the weight of passing cars. By inserting such an antenna in the right position, it would change its shape according to these factors, and would provide useful information on the bridge’s health.
Currently, the high cost of the gallium-indium alloy makes it possible to foresee its use for this kind of installations, but in a near future we might be able to see them inside our mobile phones or GPS positioning systems.