These findings are reported in a recent paper published in Proceedings of the National Academy of Sciences. The scientists discovered these properties in oxide-based “nanolattices,” tiny hollow materials whose structure resembles a sponge in the sea.
“This has happened before in simple nanostructures, such as nanowires, which are 1/1000th the thickness of a human hair,” said Yong Zhu, a professor of mechanical and aerospace engineering at North Carolina State University and one of the paper’s first authors. This is the first time we’ve seen it in a three-dimensional nanostructure.”
This phenomenon is called inelasticity. It has to do with how the material responds to stress over time. When the material studied in this paper is bent, small defects move slowly as the stress gradient changes. When the stress is released, the microscopic defects gradually return to their original positions resulting in inelastic behavior.
The researchers also found that the defects unlocked the energy-dissipating properties as they moved back and forth. This suggests their ability to dissipate vibrations and pressure waves, among other things.
This material is expected to act as a shock absorber, but since it is so light and thin, it will be on a very small scale. The researchers say it could be used as part of a chip for electronics or other integrated electronic devices.
“You could potentially put this material under semiconductor chips and protect them from shock or vibration from the outside world,” said Chih-Hao Chang, associate professor in the Walker Department of Mechanical Engineering at UT Austin.
Next, the researchers have to do is to find out how to control them. The researchers will examine the geometry of the nanostructures and experiment with different loading conditions to understand how to optimize elastic properties for energy dissipation applications.