Providing an insight into roles played by individual atomic and nano-scale features, researchers recorded the videos showing how heat moves through the materials at nano-scale with a speed of sound. The groundbreaking videos were made by the state of the art ultrafast electron microscope called FEI Tecnai Femto. This is capable of examining the dynamics of materials, which happens at the atomic and molecular scale over time which is measured in femtoseconds.

“As soon as we saw the waves, we knew it was an extremely exciting observation. Actually watching this process happen at the nanoscale is a dream come true,” said lead author David Flannigan from the University of Minnesota.

In evidence with the recent study which is published in Nature Communications, a brief laser pulse to excite electrons and rapidly heat crystalline semiconducting materials is used by researchers. These materials are likely tungsten, diselenide, and germanium.

Flannigan said the movement of heat along with material looks like ripples on a pond after a pebble is dropped into the water. The energy waves moving at about 6 nanometers per second is what shows in the video.

Watch the video here:

“Because the lengths and times are so small and so fast, it has been very difficult to understand in detail how this occurs in materials that have imperfections, as essentially all materials do. Literally watching this process happen would go a very long way in building our understanding, and now we can do just that,” he said.

In most applications, the scientists and engineers want to understand thermal energy motion, which can control it, collect it and precisely to do useful work or very quickly move away from sensitive components he said.