An intriguing property of the material dissipates energy.

Researchers from North Carolina State University and University of Texas at Austin discovered a unique property of complex nanostructures that was previously seen only in simple nanostructures. They also discovered the intrinsic mechanics of materials that allow this property to exist.

The findings were published in a recent journal article Proceedings of the National Academy of Sciences. Scientists have found these properties in oxide “nanolattices,” which are tiny hollow materials with a structure that resembles that of sea sponges.

“This has been seen before in simple nanostructures like a nanowire, which is about 1,000 times thinner than a hair,” said Yong Zhu, a professor in the Department of Mechanical and Aerospace Engineering at North Carolina State and one of the paper’s lead authors. “But this is the first time we’ve seen it in a three-dimensional nanostructure.”

Unique defects in 3D material. Credit: University of Texas at Austin/North Carolina State University

Research

This phenomenon is called inelasticity. This has to do with how materials react to stress over time. When the materials studied in this work were bent, small defects moved slowly in response to the stress gradient. When the stress is removed, the microscopic defects gradually return to their original locations, leading to elastic behavior.

The researchers also found that these defects unlock energy dissipation characteristics as they move back and forth. This indicates that they have the ability to dissipate things like vibrations and pressure waves.

Why it matters

This material could someday serve as a shock absorber, but since it is so light and thin, there would be very little of it. The researchers say it could make sense as part of chips for electronics or other integrated electronic devices.

“You could potentially put this material under semiconductor chips and protect them from external impact or vibration,” said Chi-Hao Chang, Walker Associate Professor of Mechanical Engineering at UT Austin.

What’s next

Now that these inelastic characteristics have been identified, the next step is to control them. The researchers will study the geometry of the nanostructures and experiment with different loading conditions to learn how to optimize the elastic characteristics for energy dissipation applications.

Reference: Yi-Te Chen, Felipe Robles Poblet, Abhijit Bagal, Yong Zhu, and Chi-Hao Chang, “Inelasticity in Thin-Shell Nanolattices,” 12 September 2022. Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2201589119

The research was funded by the National Science Foundation.