Scientists Make Thin Strands of Ice That Bend Without Breaking

Researchers created a new type of ice that is far more elastic than any other water ice ever studied

ice microfiber
A thin strand of ice seen through a microscope in the process of bending under pressure. When the pressure is released the ice strand will spring back to its original shape. P. XU ET AL / SCIENCE 2021

We are accustomed to ice acting a bit like glass—rigid and brittle—but in a series of experiments, researchers have been able to bend ice’s usual rules to create thin strands of ice that are flexible and elastic, reports Emily Conover for Science News.

The team behind the new paper, published in the journal Science last week, unlocked these unheard-of properties of frozen water by forming thin threads of ice just a fraction the width of a human hair.

Researchers made these so-called microfibers of ice by sending water vapor into a small chamber chilled to -58 degrees Fahrenheit and then introducing a metal needle made of tungsten charged with 2,000 volts of electricity, reports Katherine Kornei for the New York Times. The electric field around the needle attracted water molecules that then crystalized at the tip of the needle in a thread-like shape.

Next, the team made the small chamber even colder, lowering the temperature to -94 and -238 degrees Fahrenheit. They tested the physical properties of these newly created ice microfibers and found that they were far more elastic than any other known configuration of water ice.

“Previously, the largest elastic strain experimentally observed in ice was about 0.3 per cent, but now we have 10.9 per cent in ice microfibres, much more bendy than any ice before,” study author Limin Tong, a physicist at Zhejiang University in China, tells Leah Crane of New Scientist.

This strategy allowed researchers to bend the tiny strands of ice almost into a complete circle without breaking it and for the ice to spring back into shape when the pressure was released. According to New Scientist, the theoretical limit of elastic strain for water ice is between 14 and 16.2 percent.

The explanation for this exceptional elasticity may be how perfectly formed these ice microfibers were, according to Science News. Under normal circumstances ice forms with cracks, holes or imperfectly aligned ice crystals, but these lab-grown microfibers were composed of an almost flawless arrangement of ice crystals.

Closer examination of the ice strands also revealed that bending the ice changes the structure of the part of the strand that gets compressed by the bend, turning it into a denser form of ice, according to New Scientist. This could make these ice microfibers a useful way to study how ice changes from one form to another.

Per the Times, this new type of ice is not just super-elastic, it’s also excellent at transmitting light along the length of each fiber. In the paper, the researchers suggest that these properties might one day allow this type of ice to help study air pollution.