Metamaterials: From Spycraft to Infinity and Beyond

By Stephan Blanz

The future is here, but if you don’t look closely, you might miss it. Dr. Igor Bargatin, Professor of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania is creating metamaterials – materials so thin they can elude the eye. Their unique properties allow them to levitate on their own, harness energy, and possibly provide the key to unlocking interstellar flight. On April 12, 2019, Bargatin presented to the Mechanics Seminar Series at UW?Madison on “Plate Mechanical Metamaterials and their Applications.” In his talk, Bargatin shed light on some of his recent work, funded in part by the Defense Advanced Research Projects Agency (DARPA), and revealed the almost science-fiction-like findings and applications these new materials could lead to.

Materials engineered to possess properties not found in nature, or metamaterials, derive their properties from unique combinations of size and structure. The material’s structure can be precisely engineered to meet the demands of its desired application. Bargatin’s latest material structure resembles the pattern of a basket-weave. By using this pattern, the material not only becomes stronger, but it also gains the ability to “bounce back” to its original shape after being deformed. An additional benefit of his material is that it is so thin that it weighs nearly the same as air itself.

Bargatin’s research group has utilized the properties of his metamaterials and created devices which once resided exclusively in the realm of science fiction. According to Bargatin “The application we’re most excited about right now is the application of levitation and propulsion.” Bargatin and his team have created a completely self-sustaining aerial drone, approximately the size of a quarter. To do this, two properties of metamaterials have been utilized. First, the material itself is so light that gases travel through pores in the surface of the object via temperature gradients, causing it to rise in a manner similar to hovercraft levitation. Second, by utilizing principles of quantum physics, these materials can be used to turn heat and light into fuel.

The properties achievable with metamaterials could also be the key to unlocking interstellar flight. Until now, we have not had the technology capable of taking a spacecraft to our nearest star system within a single human lifetime. Bargatin has his sights set on creating a game-changer: a metamaterial interstellar sail. This sail would utilize earth-based lasers shining on the surface of the sail to propel it to within a fifth of the speed of light, or ten million times faster than the average car moving along a highway. The properties of metamaterials, namely its light weight and durability would make it an excellent candidate for such a sail.

We do not know what the future holds, or what space travel will one day look like. But metamaterials have the potential to make a profound impact both here at home and light years away.