A&A's Chun-Wei Chen contains energy for better structures, smoother rides, and higher efficiency.

Ph.D. student Chun-Wei (Ethan) Chen successfully confined vibrations using a pattern of bolts to guide the waves.

Regular intervals of hissing and squeaking of a metal plate with a curious geometric distribution of bolts continues for hours at a time in A&A’s Laboratory for Engineered Materials and Structures (LEMS). The hissing creates vibrations in the plate that a laser positions itself with a squeak to measure as they ripple throughout the map of bolts. The goal is to observe how the vibrations diffuse through the structure and if those vibrations can be confined to a small section of the plate.

For a group of A&A researchers led by Chun-Wei (Ethan) Chen, the results did not disappoint. The vibrations were successfully contained to a small section of the plate as the researchers had intended with the intentional pattern of bolts. Chen explains, “By showing that we can isolate and contain this kind of energy – in this case, a mechanical wave – we are encouraged that in the future we can build structures and vehicles that not only reduce vibrations for comfort or structural integrity, but could potentially harvest those vibrations and convert this captured energy for additional power.”

A&A researchers created a precise pattern of bolts to direct the paths of mechanical waves into a confined area of the metal plate.

Jinkyu Yang, Chen’s adviser and head of LEMS, is excited about the significance of these findings. “Ethan has actually observed in the lab what we had previously only demonstrated theoretically," Yang says. "The implications of being able to contain vibrations in a structure point to many potential future applications, such as smoother rides for airplane and automobile passengers with a potential to harness the vibration energy collected back into the system.”

After additional study, researchers will move toward designing both materials and structures that will have an adapted pattern to create the map for vibrations to follow, isolating areas of machines, vehicles, buildings, and more, such as where humans or sensitive equipment would be.