NYC Gazette

Scientists have made significant progress in enabling waves—whether sound, light, or mechanical—to travel undisturbed through complex environments. This development is achieved through topological pumping, a phenomenon that allows waves to follow predetermined paths without interference from obstacles or imperfections.

In conventional settings, topological pumping operates similarly to an Archimedean screw. However, researchers have discovered a more intriguing version using intricate pattern designs and synthetic dimensions. These additional dimensions facilitate the movement of waves across structures without being affected by irregularities like cracks or defects.

A study titled “Smart Patterning for Topological Pumping of Elastic Surface Waves,” published in Science Advances, demonstrates this concept with elastic surface waves. The research team includes Dr. Emil Prodan, professor of physics at Katz School’s M.A. in Physics program. They crafted a system using resonating pillars connected by specially designed bridges on a material's surface to guide these waves precisely.

“The key to this innovation lies in how the surface is structured," said Dr. Prodan. "Aperiodic arrays of pillars resonate at specific frequencies and interact with each other through slow-changing bridges, creating a synthetic space.”

The study confirmed that waves could traverse surfaces smoothly despite imperfections through simulations and physical experiments.

“The immune nature of topologically pumped waves is a game-changer,” stated Shaoyun Wang, lead author and student at the University of Missouri's Department of Mechanical and Aerospace Engineering.

This research is part of the broader field known as topological matter, which employs advanced mathematical concepts to discover new phases of materials inspired by phenomena like the quantum Hall effect.

Synthetic dimensions address challenges in mechanical engineering by allowing control over wave movement without external forces or active materials. By designing patterns within these hidden dimensions, scientists can direct waves along precise paths.

“This opens up new possibilities for designing materials that control waves in novel ways,” said Dr. Prodan.

Researchers conducted detailed experiments demonstrating their approach:

- System Design: A structured surface with tiny resonating pillars was created.

- Experimental Verification: Using piezoelectric patches excited the system; observed waves moved undisturbed from one edge to another.

- Wave Splitting: The team successfully guided waves along separate paths by altering synthetic dimensions.

The implications are vast—from robust communication systems to materials shielding against natural disasters—and pave the way for exploring higher-dimensional physics and complex wave behaviors. However, challenges remain regarding scaling down these systems for widespread use.

“The potential for breakthroughs in various industries is immense,” noted Dr. Guoliang Huang from the University of Missouri's Department of Mechanical and Aerospace Engineering. Future research may extend this approach to other types of waves like electromagnetic or quantum ones while exploring more complex trajectories.