Scientists Developed Super-Bendy Ice Strands That Can Bend Into a Loop Without Breaking

According to a new study published in the journal Science, the researchers developed "very thin" ice microfibers that can bend up to about 11 percent and remain elastic, defying the common belief that ice is a rigid and brittle crystal.

The team behind the new paper unlocked these previously unknown properties of frozen water by forming thin threads of ice just a fraction of the width of a human hair.

Scientists from China's Zhejiang University discovered that tiny strands of ice created in a lab do not break; instead, they bend and can become so bendy that they can be shaped into a loop.

Because of their small size and rapid formation, the ice fibers created in the lab had very few flaws, prompting experts to believe the tiny pieces could aid in the development of new and more efficient light-transmission technology.

These ice microfibers are so flexible that they are close to the theoretical limit of ice elasticity.

Water ice has a maximum theoretical elastic strain of about 15%. The maximum elastic strain ever measured in the real world was less than 0.3 percent. The reason for this disparity is that ice crystals have structural flaws that increase their brittleness.

Consequently, the researchers created ice microfibers with a maximum elastic strain of 10.9 percent by making ice with as few structural imperfections as possible.

The team created the super-bendy ice by pumping water vapor into an ultra-cold chamber chilled to around minus 50 degrees Celsius and introducing a tungsten metal needle charged with 2,000 volts of electricity. This drew water molecules to the needle's tip, where they crystallized, forming a microfiber with a maximum width of around 10 micrometers, which is smaller than the width of a human hair.

The temperature was then reduced to between minus 70 and minus 150 degrees Celsius. The researchers attempted to bend the ice fibers at these low temperatures.

At minus 150 degrees Celsius, researchers discovered that a microfiber 4.4 micrometers across could bend into a nearly circular shape with a radius of 20 micrometers. This implies a maximum elastic strain of 10.9 percent, which is closer to the theoretical limit than previous attempts.

"Making optical fibers from ice or water, which are common materials, can help develop micro/nano ice-based technologies in specific application scenarios, such as using them as a research platform to analyze viral spectra," said Tong Limin of the Zhejiang University team, who collaborated with researchers from the University of California, Berkeley.

Closer examination of the ice strands revealed that bending the ice changes the structure of the part of the strand compressed by the bend, turning it into a denser form of ice. This could make these ice microfibers useful for studying how ice transforms from one form to another.

Scientists also noticed that these ice strands were extremely transparent, so they attached a tiny flashlight to the ends of each strand and discovered that light could be transmitted through the fibers just as easily as it could through state-of-the-art waveguides, implying that ice microfibers could be used as flexible waveguides for optical wavelengths at low temperatures.