The working is very simple, when the positive voltage is applied to the liquid metal it will expand whereas if negative voltage is applied then it contracts.
When the liquid metal is placed inside capillary and small negative voltages are applied it causes the metal to withdraw from the capillary and if positive voltage is applied it causes the metal to expand and flow into the capillary.
Such elongation and shortening of liquid metal filament changes the antenna’s operating frequencies.
Liquid electronics technology has interested many researchers but there have too many drawbacks previously to fully develop the technology.
Jacob Adams an assistant professor in the Department of Electrical and Computer Engineering at NCSU and co-author of the study said, “Using a liquid metal, such as eutectic gallium and indium that can change its shape, allows us to modify antenna properties more dramatically than is possible with a fixed conductor.”
The antenna’s properties can be reconfigured to some extent by using solid conductors with electronic switches.
By using the liquid metal approach the operating frequency of the antenna can be tuned to a greater range.
Adams said, “Our antenna prototype using liquid metal can tune over a range of at least two times greater than systems using electronic switches.”
Researchers also hope that the device can have many applications in future including the mobile phones.
Adams said, “Mobile device sizes are continuing to shrink and the burgeoning Internet of Things will likely create an enormous demand for small wireless systems. As the number of services that a device must be capable of supporting grows, so too will the number of frequency bands over which the antenna and RF front-end must operate. This combination will create a real antenna design challenge for mobile systems because antenna size and operating bandwidth tend to be conflicting trade-offs.”
Tuneable antenna can be adapted and miniaturized to solve the near field loading problems.
The new approach, liquid metal system provides tuning of the antennas to a greater range than the conventional reconfigurable antennas.
Researchers also believe that the same approach can be used for tuneable filters and other such components.
Now the researcher’s next target is to improve the speed and efficiency of the antenna configuration.
Researchers hope that they can get greater control over the shape of the liquid metal, by creating two-dimensional capillaries and surfaces of nearly any desired antenna shape.