While the possibility of humans being able to disappear is highly unlikely, this hasn’t stopped movie directors and writers from including it in their stories for many years. Scientists have once again stepped forward in an attempt at making the impossible possible by producing a material which may allow us to do so. Researchers at Iowa State University have developed a material that ‘disappears’ under certain conditions, which they hope will one day become the foundation of ‘invisible cloaks.’
The camouflage material is a type of liquid metal, which is made of tech that has been imbedded in a flexible sheet of silicon. This in turn is comprised of several rings (filled with galistan) that cover the material’s surface and act as inductors resisting changes in electric currents passing through them, with the gaps acting as capacitors. This combination facilitates radar waves hitting the material’s surface to be absorbed by the film.
The researchers describe their creation as a material made of an array of liquid metal spilt ring resonators (SRRs) which are embedded in a stretchable elastonomer. When it is stretched this ‘meta-skin’ has a tunable frequency, which is able to accommodate a wide range of other frequencies thus absorbing radar waves. Experimentation with wrapping it around a curved dialectic material shows that the meta-skin performs as a flexible cloaking surface, which is able to suppress the scattering of frequencies in different directions.
The flexibility of the material means that radar waves which don’t follow the ring’s geometry will still be absorbed as the meta-skin will conform to different signals. The same sheet of material is currently able to absorb 75% of radar signals, ranging from 8 to 10 gigahertz. The developers plan to use the technology to coat the surface of stealth aircraft, eventually expanding its properties to incorporate a wider range of radar waves. The material’s ability to absorb waves differs from traditional stealth technology which normally just reduces the power that is reflected back to the probing radar, and would greatly increase stealth capabilities.
In order for invisibility cloaks to be produced the material will need to be able to absorb light, since the reflection of light is the way in which we currently see objects. Researchers will need to expand experimentation to include nano scale technology in order to accomplish this, which will increase the difficulty of working with this met-skin significantly. They are completely confident that this will be possible, however, and we can look forward to the ‘disappearance’ of humans very soon.