Fascinating Slow-Motion Video of Single Molecules at 1,600 Frames Per Second Captured by Scientists

Scientists have captured fascinating slow-motion video of single molecules in motion at 1,600 frames per second, according to a study.

The team from the University of Tokyo (UT) say that the latest feat exceeds the previous frames per second record for this kind of experiment by more than a hundred times. The higher the temporal resolution of a camera—in other words, the more frames that a device captures—the clearer the motion of the molecules becomes.

Over the past decade or so, scientists have been able to capture videos of atomic-scale events up to about 16 frames per second. For context, films shown in the cinemas are usually displayed at 24 frames per second.

The UT scientists used a new method combining a powerful electron microscope with a highly sensitive camera and advanced image processing techniques to capture video of the molecules at 1,600 frames per second, according to a study published in the journal Bulletin of the Chemical Society of Japan.

Electron microscopes use beams of accelerated electrons—negatively charged subatomic particles—to investigate tiny objects that are far too small for ordinary microscopes to reveal, such as microorganisms and large molecules. In this sense, electron microscopes can be said to have very high "spatial resolution" because they are capable of seeing minute details. In fact, the microscope used in the study is capable of resolving objects smaller than one ten-billionth of a meter.

"Previously, we successfully captured atomic-scale events in real time," Eiichi Nakamura, an author of the study from UT, said in a statement. "Our transmission electron microscope (TEM) gives incredible spatial resolution, but to see details of small-scale physical and chemical events well, you need high temporal resolution too. This is why we pursued an image capture technique that is much faster than earlier experiments, so we can slow down playback of the events and see them in a whole new way."

The scientists attached a highly sensitive camera to the TEM that is capable of capturing high frame rates. However, this method creates a lot of noise in the images, meaning the researchers had to create a workaround.

"To capture high fps, you need an imaging sensor with high sensitivity, and greater sensitivity brings with it a high degree of visual noise. This is an unavoidable fact of electronic engineering," Koji Harano, another author of the study from UT, said in the statement. "To compensate for this noise and achieve greater clarity, we used an image-processing technique called Chambolle total variation denoising. You may not realize, but you have probably seen this algorithm in action as it is widely used to improve image quality of web videos."

The researchers tested their experimental technique on vibrating carbon nanotubes—minuscule tubes made of carbon with diameters typically measured in nanometers—that contain complex carbon atoms known as fullerenes.

Fullerenes, or "buckyballs," are hollow spheres of carbon atoms, which are connected in a lattice of pentagons and hexagons resembling the pattern seen in the structure of some soccer balls. This group of molecules take their name from the most well-known member "Buckminsterfullerene," which contains 60 carbon atoms and is itself named after the renowned American architect Buckminster Fuller, who is credited with popularizing the geodesic dome structure.

With their setup, the researchers were able to image some behavior that has never been seen before on the nanoscale, because it is only visible at high frame rates. For context, a nanometer is a billionth of a meter. While their technique still has issues that need to be addressed, the researchers say it could have significant implications for those investigating the world at this scale.

"We were pleasantly surprised that this denoising and image processing revealed the unseen motion of fullerene molecules," Harano said. "However, we still have a serious problem in that the processing takes place after the video is captured. This means the visual feedback from the experiment under the microscope is not yet real-time, but with high-performance computation this might be possible before too long. This could prove to be a very useful tool to those who explore the microscopic world."