ScienceNot yet confirmed elsewhere1 publisher2 min readPublished
Hebrew University's BioPykrete absorbs 70 times more energy than plain ice in early tests
Hebrew University researchers bonded cellulose crystals to ice with a designed protein, making it 10 times stronger and able to absorb 70 times more energy. Both gains are against ordinary ice, so the small study cannot yet say whether the protein bond beats the wartime wood-pulp recipe.
The Scientist · Science desk
Supported: BioPykrete is 10 times stronger than ice and absorbs 70 times more energy. Supported: Pykrete was apparently as strong as concrete if kept frozen. Supported: the study was a small-scale proof of concept. Insufficient: ScienceAlert's headline putting the new ice close to concrete.
- Supported By adding plant-based crystals and a bespoke protein to ice, the researchers created a material 10 times stronger than regular ice and able to absorb 70 times more energy before breaking., claim 5
- Supported Pykrete was apparently as strong as concrete, as long as it could be kept frozen., claim 2
- Supported The study was a small-scale proof-of-concept test; further research is needed on how BioPykrete stands up over long periods and under changing conditions., claim 9
- Insufficient evidence ScienceAlert's headline describes the new ice as 10 times stronger, bringing it close to the strength of concrete., claim 18
| Claim | State | Claim number |
|---|---|---|
| By adding plant-based crystals and a bespoke protein to ice, the researchers created a material 10 times stronger than regular ice and able to absorb 70 times more energy before breaking. | Supported | 5 |
| Pykrete was apparently as strong as concrete, as long as it could be kept frozen. | Supported | 2 |
| The study was a small-scale proof-of-concept test; further research is needed on how BioPykrete stands up over long periods and under changing conditions. | Supported | 9 |
| ScienceAlert's headline describes the new ice as 10 times stronger, bringing it close to the strength of concrete. | Insufficient evidence | 18 |
What happened
- The bonding agent is CBM3a-AFPIII, a designed protein that joins an antifreeze protein to a carbohydrate-binding module and holds cellulose nanocrystals to the ice.
- The team used cellulose nanocrystals in place of the larger, disordered wood-pulp fibres in Pykrete, the 1940s frozen composite its work builds on.
- The team hopes the material could one day be used for building in remote cold regions such as the Arctic and Antarctic, where conventional methods are hard to apply.
- The work was a small-scale proof of concept, and the material has not yet been tested over long periods or under changing conditions.
Why it matters
- contradiction ScienceAlert's headline puts the new ice close to concrete, but the figures it reports are only ratios against plain ice, so readers cannot check that comparison from the published account.
- cost Pykrete was dropped as costs rose and better options appeared; BioPykrete adds a recombinant protein to the recipe, so it has to pass the same cost test before a polar builder would pick it.
- capability Because the bond is a designed protein, the team has something it can vary: the researchers say new AFP-CBM variants and changed freezing protocols could produce stronger composites.
The two multiples measure different things, and they moved by different amounts. The gain in energy absorbed before breaking is seven times the gain in strength [14]. On these figures, more of the change is in how the ice fails than in how much load it takes [14]. Ido Braslavsky, a biochemist at the Hebrew University of Jerusalem, 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." [8]
Failure was the target from the start. "We wanted to go beyond simply mixing fibers into ice and instead control how the different materials connect at the molecular level," Braslavsky said [7]. In nanocrystal form, cellulose acts as a microscopic reinforcement that keeps cracks from spreading easily, according to ScienceAlert [11].
The comparison that would settle the design question has not been run. Pykrete, the wood-pulp ice the British Royal Navy tested as material for a Second World War aircraft carrier [1], was apparently as strong as concrete as long as it stayed frozen [2]. The Hebrew University team describes BioPykrete as an extension of that 1940s idea [4]. A tenfold gain over unreinforced ice [5] does not, on its own, show that bonding at the molecular level outperforms mixing fibres in. ScienceAlert's account of the paper in Colloids and Surfaces B: Biointerfaces [6] does not include absolute strength values, the type of load test, the number of samples, or a side-by-side run against wood pulp.
The researchers write with some confidence: "By bridging the gap between recombinant protein design and structural engineering, we have developed a high-performance material specifically engineered for the rigors of the world's most extreme environments." [19] They also want to study how cracks propagate through BioPykrete, to confirm that the strengthening works the way they think it does [13]. We think the second statement is the accurate one for now. The fracture result is a good experimental finding, and which part of the recipe produces it is still unconfirmed [13].
The appeal is the ingredient list. With ice and plant cellulose as the main inputs and no concrete or steel, the material could have a low carbon footprint and be biodegradable, according to ScienceAlert [16].
What to watch
- Whether the planned crack-propagation work confirms that the protein-bonded interface is what makes the ice deform gradually before it breaks.
- Tests of BioPykrete over long periods and under changing conditions, the exposure a polar structure would actually face.
- Absolute strength figures, or a direct test against wood-pulp Pykrete, that would let the concrete comparison be checked.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence35
- Adoption
- Insufficient
- Hype gap+40
- Incentives
- Insufficient
- Confidence40
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
During the Second World War, the British Royal Navy experimented with using ice reinforced with wood pulp, known as Pykrete, to build an aircraft carrier.
- [2]
Pykrete was apparently as strong as concrete, as long as it could be kept frozen.
- [3]
The Pykrete aircraft carrier project was abandoned amid rising costs and as better options became available.
- [4]
Researchers led by a team from the Hebrew University of Jerusalem extended the 1940s Pykrete idea to create what they call BioPykrete.
- [5]
By adding plant-based crystals and a bespoke protein to ice, the researchers created a material 10 times stronger than regular ice and able to absorb 70 times more energy before breaking.
- [6]
The study was published in Colloids and Surfaces B: Biointerfaces.
- [7]
"We wanted to go beyond simply mixing fibers into ice and instead control how the different materials connect at the molecular level."
ReportedSupportedSource: Ido Braslavsky, biochemist, Hebrew University of JerusalemView cited source - [8]
"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."
ReportedSupportedSource: Ido Braslavsky, biochemist, Hebrew University of JerusalemView cited source - [9]
The study was a small-scale proof-of-concept test; further research is needed on how BioPykrete stands up over long periods and under changing conditions.
- [10]
Instead of wood pulp's larger, disordered fibres, the researchers used cellulose nanocrystals.
- [11]
In nanocrystal form, cellulose can act as a microscopic strengthening agent for other materials including ice, essentially stopping cracks from spreading easily.
- [12]
The protein, CBM3a-AFPIII, combines an antifreeze protein (AFP) and a carbohydrate-binding module (CBM); its job is to act like glue keeping the cellulose nanocrystals and ice bonded together.
- [13]
The researchers want to look more closely at how cracks propagate through BioPykrete, to confirm that the underlying strengthening mechanisms are what they think they are.
- [14]
The reported gain in energy absorbed before breaking (70x) is seven times the reported gain in strength (10x).
- [15]
The intended application is construction in remote, cold areas where conventional building methods are hard to apply, such as the Arctic and Antarctic; the team hopes it may one day be used as a building material.
- [16]
With no concrete or steel required and ice and plant-based cellulose as the main ingredients, the material could have a low carbon footprint and be biodegradable.
- [17]
"Optimizing solidification kinetics and freezing protocols, alongside developing diverse AFP-CBM variants, could yield even higher-strength composites."
- [18]
ScienceAlert's headline describes the new ice as 10 times stronger, bringing it close to the strength of concrete.
- [19]
"By bridging the gap between recombinant protein design and structural engineering, we have developed a high-performance material specifically engineered for the rigors of the world's most extreme environments."
Sources
1 independent publisher whose own reporting we read for this story.
- sciencealert.comA New 'Super Ice' Is 10 Times Stronger, Bringing It Close to The Strength of Concrete
1 article · October 11, 2026
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