When it comes to microfibres, researchers will no longer need to “break the ice”. Thanks to a new discovery in nanomaterials, they will now be able to bend it.
“Our group has been working on silica microfibers for 20 years,” he says Xin Guo, an optical scientist at Zhejiang University in China and one of the authors of the study published in Science. Now, his team has become the first to grow flexible ice microfibers that it can fold in on itself, without breaking.
The creation of a flexible and "elastic" ice
Ice is known to be a brittle substance, mainly due to imperfections in the structure of its crystals. Science still does not fully understand what happens at the molecular level when ice turns into water and vice versa. The optical properties of the new ultra-elastic ice microfibers could bring the understanding of the phenomena affecting them closer materials.
The experiment
The researchers created the microfibers by cooling a tungsten needle (single-atom thick, the sharpest object ever made) in a special chamber to about -60 degrees Fahrenheit. They then used an electric field to attract water vapor to the tip of the needle. When the vapor froze, it formed a microfiber of about 5 micrometers in diameter and about 1 millimeter in length. The team at this point lowered the temperature further between -94 degrees and -238 degrees Fahrenheit. When they tried to fold it, they found that their experiment had worked.
The resulting fiber could bend up to a maximum deformation of 10,9%, much more than normal ice, while also returning to its original shape.
It's like magic. We don't normally have perfect ice crystals. We now have a kind of microfiber with a very uniform character.
Limin Tong, Zhejiang University
What can flexible ice do?
The researchers sent light through this ice microfiber, which is very clear, and found that it works as well as optical fiber. What's more: this fiber could also be used in the detection of viruses or other microbes; by placing tiny organisms on microfibers and guiding light through them, we may learn more about the concentration, density or types of microbes that may be present.
In the future, the team will also work on building sensors compatible with flexible ice. Of course, this fiber melts at around 14 degrees Fahrenheit, meaning it may not be useful in many situations. “This is a widely used temperature in laboratories,” says Tong, “and also in some types of ice cream.” But researchers in the polar regions, or in space, could make use of them due to the inherently low temperatures.
Perhaps more importantly, the light shining through these frozen fibers could help researchers study what happens when ice changes phase. Since a phase change can be achieved by simply folding the microfiber, this could reveal more about how ice crystals form, why they form that way, and what molecules are involved.
For now, the next step is to determine if you can make longer ice microfibers. I'll keep you up-to-date.
