Using inverse design principles and a 3D printer, the team say they can create an efficient, non-resonant, broadband metadevice at millimeter-wave frequencies.
Koray Aydin, assistant professor at the McCormick School of Engineering, said: "I feel like we're really on the verge of something big. There's a lot that needs to be done in the research part, but we're going in the right direction."
Inverse design starts with a function and asks what structure is needed to achieve the desired result, unlike forward design.
The team’s aim was to create metadevices that could bend or focus millimetre waves. They did by using computer modeling, optimisation software and complex algorithms, which they said helped to avoid problems that arise with more conventional approaches.
Prem Kumar, a professor at both McCormick and Weinberg College of Arts and Sciences, said: "What we've achieved here is a new way of creating electromagnetic devices that achieve certain functions that conventionally seemed impossible to do.”
Aydin described the pinnacle moment as the algorithm spit out the design for a complex geometric shape. "These were not known shapes, not intuitive shapes.” But this presented a problem, with Aydin questioning how they would go about building this, as typical manufacturing methods would prove both tricky and expensive. The answer was additive or 3D printing.
"This is the heart of the study," Aydin said. "We're the first to combine these two to make working devices."
"The important thing to me is the multidisciplinary nature of it. We can design a lens in a way that it doesn't look like a lens, Kumar added.
Aydin also pointed out that it was imminently scalable from the microwave to the visible frequency range because of the flexibility of 3D printing, which he believed was another strength of their process.
"It is an exciting result," said Alan V. Sahakian, the John A. Dever Chair and professor of Electrical Engineering and Computer Science. "Where in the past somebody might have done a long analysis trying to approximate the behaviour, here we essentially input the behaviour we wanted into a computer and the computer optimizes a structure that has that behaviour and then it comes out the other end of this three-dimensional printer. It is truly a breakthrough in the way you can solve problems in a seamless and convenient way."
