There are a lot of reasons to want to make things invisible, other than it just being incredibly cool. There are the many potential military uses of cloaking technology, of course, but it could also help improve cellular signals by hiding objects that would normally block and weaken signal strength.
Cloaking technology is popular science fiction trope, but real scientists have been researching and developing new ways to make cloaking objects a reality for years. Most recently, two researchers at the University of Toronto have found a new way to cloak an object using tiny antennas.
In a paper published this week in the journal Physical Review X, they describe their new take on cloaking. They’re not making objects invisible to the human eye but making them undetectable by radar. They can even control the signals bouncing back to make objects seem larger or smaller than they really are.
Radar works by sending out electromagnetic waves that reflect off objects and bounce back to the detector. In the past, researchers have made things invisible to radar by redirecting the waves around the object. University of Toronto researchers Dr. George Eleftheriades and Michael Selvanayagam took a different approach more suited to large objects.
The nanoantennas they used radiate an electromagnetic field that prevents waves from reflecting back to the radar detector. The small antennas can be even printed flat to create a flexible skin for the desired object. While the technology only works for radio waves at the moment, the researchers say the same principals could be applied to other waves such as light waves, which could potentially hide an object from the human eye.
In their demonstration, Eleftheriades and Selvanayagam tested the antennas on an aluminum cylinder. Currently, the antennas need to be manually set to the proper frequency they’re blocking, but in a more advanced set up, they could detect the different waves and adjust accordingly.
There have been numerous other attempts to make things disappear.
In March, researchers at the University of Texas in Austin created a material that could be used to cancel out the microwaves bouncing off an object. Researchers at Michigan Technological University have experimented with cloaking objects from microwave and infrared frequency waves using shells of nonconductive materials such as ceramics and glass metamaterial to distort waves.
It’s going to a long while before we’re picking up our own personal cloaking devices at the local Best Buy. But new research in this field is constantly tacking new, wider bandwidths and experimenting with less cumbersome technology that can be used on larger devices.