Off in the future, IDF soldiers may get the ultimate battlefield armor — a Harry Potter-style “invisibility cloak” that could let them cross a battlefield right under the noses of their enemies – without being detected. In the meantime, the goals for using technology like that are a bit lower – but still important.
Until those cloaks are ready for action, Professor Michael Bank of the Jerusalem College of Technology is using the “metamaterials” that could be used to build those invisible uniforms to protect soldiers in the field from electromagnetic radiation emitted by communications equipment. “It’s true that metamaterials can be used for invisibility cloaks, and that’s a project we may work on one day,” Bank told The Times of Israel. “But for now, we are using it to keep radiation away from soldiers’ heads and upper body.”
Bank is one of Israel’s senior experts on communications and electricity, and the radiation that results from both. An immigrant from Russia, Bank has numerous patents to his name, including one that allows electricity to flow through a single wire instead of the two that are generally needed, saving as much as 50% in power use and cost.
Bank also has done innovative work in the area of antennas — and it’s those innovations that he is supplying to the IDF to help protect soldiers from radiation. “Units in the field always have at least one soldier who is required to carry a large communications unit, and they usually carry them on their shoulders or back, right next to their head,” said Bank. “The systems have large transmitters and emit a large amount of electromagnetic radiation, which many scientists believe are the cause of diseases such as cancer. We designed a new antenna that keeps the radiation away from the heads of soldiers, without compromising the range or performance of the transmitter.”
Bank’s invention uses a metal deflector to keep radiation away from the head of the soldier carrying the communications gear. “The deflector is in the shape of a small satellite dish, which goes between the soldier and the antenna. The deflector is designed in such a manner that it “pushes” the electromagnetic waves in the direction of the curve of the dish, away from the head of the soldier.” The IDF has approved the system and has begun installing it on an experimental basis with some field units in anticipation of a wider rollout during the coming year.
While researchers are unsure if there is a connection between electromagnetic waves and cancer — there is evidence for and against — Bank said that keeping the waves away from soldiers certainly couldn’t hurt. “Considering that this device is cheap and easy to install, there’s no reason not to use it,” he said.
The IDF deflector is based on a smaller version Bank helped develop for cellphones, which he and several of his partners shopped around to cellphone manufacturers. “But they weren’t too interested,” Bank said. “They told us that they had their designs and that no one was complaining about this, so there was no need for them to use this. I guess if people were to make noise, they might change their minds,” he added.
The deflector is only one of Bank’s antenna projects. “We also came up with the idea of putting the antenna on the leg of a soldier, on the theory that the lower body is less susceptible to potential damage from electromagnetic radiation than the upper body.” Here, too, Bank and his fellow JCT researchers aimed to come up with a system that would keep radiation away from the body.
That’s when they discovered metamaterials – engineered materials that are micro-designed in a manner that results in a specific behavior. Depending on how the components – usually metal threads – are arranged, the materials can deflect radiation, sound, and even light. The materials are precisely constructed based on complicated principles of physics and mathematics, but once a metamaterial “recipe” is created, it can be mass-produced.
Combining the principles of metamaterials with the research he’s done on antennas, Bank came up with an interesting concept – the creation of a “leg antenna” that would consist of a sleeve that goes around a soldier’s thigh, containing a small external antenna, radiating electromagnetic waves away from the soldier. “It sounds complicated but it’s actually simple in principle,” said Bank. “When you have a rod antenna, all the electromagnetic activity is outside the antenna; if there is space inside the rod, as many telescoping antennas have, you won’t find activity there.”
Again, following principles of physics, the “inside field” keeps all radiation outside the interior of the antenna. With metamaterials, the “inside field” — in this case, the soldier’s leg — does not absorb the radiation associated with the communications system, either. The leg antenna is still in development, and Bank is set to discuss the idea with IDF brass in the coming weeks – “that is, if they are available, not a sure bet, considering the war,” Bank noted.
Though metamaterials have been around for about 15 years, they are still largely experimental – so if it is adopted, the leg antenna would be one of the first commercial applications of the materials. Metamaterials made news a few years ago, when they were used for their light-deflecting qualities to create an “invisibility cloak” that made an object in plain sight disappear. As in the Harry Potter movies, where the young wizard dons a cloak that makes his body disappear, metamaterials could be used to enable IDF soldiers to roam the streets of Gaza undetected as they search for terrorists. The US Army is already working on an experimental metamaterial cloak project, according to reports.
So is such cloak on the way for Israeli soldiers? Maybe, said Bank, but probably not anytime soon. “I’ve seen this technology, but I haven’t tried to work on it yet,” said Bank. “We may try it, but the truth is that I have a lot of research going on, so I may not get to it for a while.”