By reinforcing ice with tiny plant-based crystals and a specially designed protein, researchers created a material that rivals concrete in strength and absorbs 70 times more energy before breaking.

Ice is cheap, abundant and surprisingly strong. But it has one major weakness: cracks can race through it, causing it to shatter without warning.

Now, scientists have developed a new material that could overcome that problem. Called BioPykrete, the reinforced ice is about 10 times stronger than
ordinary ice and can absorb roughly 70 times more energy before breaking.

Rather than shattering suddenly, it bends and breaks more gradually, a quality that could one day make it useful as a building material in some of the coldest places on Earth.

The research, published by Colloids and Surfaces B: Biointerfaces, was led by Prof. Ido Braslavsky of Hebrew University’s Robert H. Smith Faculty of Agriculture, Food and Environment.

Building a Stronger Kind of Ice
The idea of reinforcing ice is not new. During World War II, researchers experimented with Pykrete, a mixture of ice and wood pulp that was stronger and slower to melt than ordinary ice.

The team took that idea down to the molecular level.

They mixed ice with cellulose nanocrystals, extremely small, stiff particles made from cellulose, the natural material that gives plants their structure. As the mixture froze, the particles formed a three-dimensional network around microscopic sections of ice.

The scientists then designed a protein that could attach to both materials. One part of the protein binds to ice, while the other binds to cellulose. Acting like a molecular glue, the protein helps hold the entire structure together.

“We wanted to go beyond simply mixing fibers into ice and instead control how the different materials connect at the molecular level,” Braslavsky said. “The result changes not only how strong the ice is, but also how it breaks. Instead of suddenly shattering, it can absorb much more energy and deform gradually.”

Keeping Small Cracks From Becoming Big Ones
In ordinary ice, even a tiny crack can spread quickly and cause the entire structure to fail. In BioPykrete, the cellulose network and protein connections appear to slow down those cracks and prevent them from moving freely. Once a crack begins to propagate through the ice, it will encounter the cellulose network that acts as an obstacle to further propagation. The molecular glue, a chimeric protein with one domain that binds ice and another that binds cellulose, anchors the cellulose network to the ice. This anchoring increases the energy required to deform or tear the network, making it a more effective barrier to crack propagation. As a result, crack growth is arrested or redirected, helping to keep cracks small and confined.

Laboratory tests found that BioPykrete was about 10 times stronger under compression than pure ice, reaching strength levels similar to conventional concrete. It also absorbed around 70 times more energy before failing.

The engineered protein played an important role: adding it doubled both the strength and the energy the material could absorb compared with a similar ice-and-cellulose mixture that did not contain the molecular bridge.

Could We One Day Build With It?
The researchers imagine BioPykrete being used mainly in Arctic and Antarctic regions, where transporting concrete, steel and other construction materials can be expensive and difficult.

Because the material is made mostly from ice and plant-based cellulose, it could potentially provide a biodegradable, lower-carbon footprint alternative for certain structures in extreme cold conditions.

But no one will be building homes from BioPykrete just yet. The material is still a proof of concept and must undergo further testing. Scientists need to learn how it performs over long periods, how it responds to repeated freezing and thawing, and whether it slowly changes shape under constant pressure.

Future studies will also examine how cracks move through the material and test new proteins and freezing methods that could make this “super ice” even stronger.