The ability to turn invisible is something that has shown up in various works of fiction for a very long time. Bilbo Baggins had his magic ring that could hide him from prying eyes, and Harry Potter had his dad’s invisibility cloak. One group of scientists have been working hard on a material that can hide objects from being detected, and today they’ve announced a breakthrough in their work.
The researchers at Iowa State University aren’t working on same type of invisibility cloak that you’ve read about in stories. That kind of technology is still beyond our ability to create. Instead, they’ve been working on a material that will shield objects from being detected by radars.
The idea that the group had been working on was to create a meta-skin, which used rows of small liquid-metal devices. By stretching and flexing the “skin” they would be able to reduce the amount of reflection from a wide range of radar frequencies.
They ended up coming up with a type of resonator made from a metal alloy named galinstan. Galinstan was chosen due to the fact that it remains a liquid at room temperature, but is less toxic that other similar materials, such as mercury.
The resonators have an outer radius of just 2.5 mm, with a gap of just 1 mm. The rings are used to create an electric inductor, while the gaps create electric capacitors. When you combine these elements together, they’re able to trap and suppress waves created by radars that operate at a variety of frequencies.
Tests of the material have shown that it can suppress around 75 percent of the waves in the range of 8 to 10 gigahertz. The team hopes that one day this material can be used to coat the likes of a B-2 Stealth Bomber, to make it virtually undetectable.
Source: Iowa State