Dr. Nathan Cohen ’77 explores the ethics of his patented invisibility cloak
In a Jan. 20 interview with The Justice, the Brandeis alumnus and CEO of Fractal Antenna discusses the real-life implications of the cloak.
To most people, an “invisibility cloak” sounds like something straight out of a fantasy series. For Dr. Nathan Cohen ’77, however, the reality of his project is potent. Since Cohen first invented the cloak in 2003, the military potential of the invisibility cloak has been an unavoidable truth. In fact, just last week Russia unveiled plans to use cloaking technology as a part of its invasion of Ukraine. Today, Cohen has a staggering 16 cloaking-related patents and a total of 93 United States patents, including one for a mechanism able to detect cloaked items.
Cohen’s first inspiration for the invisibility cloak came to him while he was working on a project for the Defense Advanced Research Projects Agency. An expert in electromagnetics, he realized the potential applications of the fractals — infinitely complex patterns that are self-similar across different scales — with which he worked. Cohen decided to chase this new phenomenon after completing the DARPA project, curious about where it could take him. In 2012, Cohen was issued the first patent on an invisibility cloak — a device able to divert electromagnetic waves around an object, “cloaking” it. In 2011, Fractal Antenna released this video narrated by Cohen explaining their new technology.
A breakthrough invention, the invisibility cloak quickly attracted attention from a variety of sources, many of them military, a daunting reality that Cohen foresaw during the inventing process. “If you build a cloak, it’s not just a Harry Potter thing. It’s an ability to hide what could be dangerous, unfriendly resources and create problems for a hell of a lot of people,” Cohen explained during a Jan. 20 interview with The Justice. In fact, Cohen nearly considered abandoning the project while he was working on it, deciding to continue out of hope that securing a patent on the cloak would give him more power to ensure ethical usage.
But Cohen didn’t stop there. In August 2022, Fractal Antenna secured a new patent — one that could detect objects hidden by the invisibility cloak. In the words of Microwave Journal’s article on the matter, this new technology was a statement that invisibility cloaks are not meant to be “toys of war.” In Cohen’s words, “I don't want to see anybody get killed. And if there's some way to take away the ability to hide stuff, clearly that is a preferred scenario.” Cohen explained to The Justice that despite radio detection waves being used to divert around cloaked objects, one can use higher or lower radio frequency overtones to detect the weak signals involved in that process. “Harry Potter can’t hide anymore,” Cohen quipped.
Cohen’s anti cloaking device follows a popular thought process known as the “balance of terror,” or the idea that war is fostered by one party feeling as if they have power over all others and therefore feel empowered to attack. “If you’re able to hide your military resources, then it emboldens one to have the capability of saying we’re going to move ahead and attack because there’s not going to be much resistance,” he explained. “That’s what scares the heck out of me.” To Cohen, inventing his anti cloaking device was doing his part to contribute to the “balance of terror” and to discourage using the invisibility cloak for military purposes.
But what about the invisibility cloak’s other usages? While many minds go straight to the military applications, the invisibility cloak has a variety of often overlooked practical applications. As Cohen puts it, “the interference caused by parts of [electronic] equipment itself confines your range and size ... rather than having things that are obstructions and interfere with other electronic components, the obstructions aren’t there anymore.” Cohen explained that using the invisibility cloak to negate the interference caused by multiple signals enables a new age of electronic design. With the possibility of lower electromagnetic interference, there is more freedom for designers to play with the size and volume scales of their inventions. “People don’t want to see cell towers,” he added. “By removing interference you can get fewer of them for the same coverage, then it’s a win-win situation.”
Reflecting on his experience as an innovator, Cohen emphasized the importance of an ethical and socially-oriented invention experience. “You have to understand how can an invention be abused? And I can tell you right now that’s just not how inventors think ... They sort of feel like, well, my job is to come up with this gadget and it’s cool and it works.” Over his time working on the original invisibility cloak and its subsequent patents, Cohen has cultivated a different understanding of the inventing process. “The first issue is coming up with the invention and saying, what am I trying to solve? … What makes it easier for people to interact with their world and move forward? That’s a social issue.” In today’s innovative landscape, he posits that education on ethics is more critical than ever.
As a retired professor who had spent time at Boston University, Cornell University, Harvard University and the Massachusetts Institute of Technology, Cohen was able to reflect on how Brandeis’ emphasis on social justice impacted him as an inventor. “Much of the community, besides studying, is tied up in social issues. You’d have to be a bug in a rock not to be exposed to it.” He commented positively on the recent Israel-Hamas Teach-in Day and commends Brandeis’ commitment to giving its students a sense of exposure and maturity on pertinent social issues. When asked what he thought the Brandeis community should know, he commented, “There’s a lot of opportunities to move the world forward. [To] take advantage of technology, [make] new technology, take advantage of science ... The real gem about Brandeis is no matter what your major is, everybody understands a sense of community, and we’re all in it together.”