New Metamaterial Design Enables Advanced Wave Control

A research team from Seoul National University's College of Engineering, in collaboration with the Korea Research Institute of Standards and Science (KRISS), has introduced a new elastic metamaterial platform enabling flexible design of how external forces and vibrations propagate. This development addresses a key challenge in nonlocal metamaterials, where interactions can extend beyond adjacent regions.

The team's design principle allows for easier extension of nonlocal metamaterials into diverse structural configurations. They experimentally demonstrated that their approach overcomes interference issues common in conventional nonlocal metamaterials, leading to more accurate control over elastic wave propagation and motion. This new technology is seen as a foundational platform for future vibration control systems, high-performance sensors, ultrasonic devices, and advanced mechanical systems.

Elastic metamaterials, characterized by engineered microstructures, offer unprecedented control over waves and vibrations and are emerging as crucial materials in wave engineering. While recent research has focused on enhancing wave transmission for applications like medical ultrasound and sensors, and suppressing waves for noise reduction and stealth, conventional metamaterials are often limited to narrow frequency bands.

Nonlocal metamaterials offer a broader frequency range by designing unit structures for interactions with distant regions. However, practical implementations have been hindered by complex geometries, fabrication difficulties, and unwanted wave interference. The Metaspire platform, by employing rotating unit structures in a sequential pattern, naturally creates space for long-range interaction pathways without increasing structural complexity.

This approach effectively suppresses undesirable wave phenomena and allows for flexible design of wave transmission and suppression across a much broader frequency spectrum, overcoming the narrow frequency limitations of previous designs. The proposed platform is generalizable and can be extended to two- and three-dimensional structures, moving nonlocal metamaterial research from theoretical studies toward practical applications.