DARPA ICE developing biological solutions for fighting and operating in extremely cold Arctic environments

The warming of the arctic has opened access to new trade routes and necessitated an expanded
operational area where the U.S. military must counter peer adversaries seeking to exploit emerging theaters in ECW areas. Significant physiological and material barriers exist to establishing and maintaining a force capable of sustained operations in ice-prone environments.

Fighting in the bitter cold and in environments dominated by ice is tough and dangerous. DARPA is now seeking proposals for technologies that alter and control ice at the molecular level, thus mitigating the risk for troops fighting and operating in extremely cold environments.

Many of these challenges are a consequence of the physical properties of ice such as ice crystal formation, recrystallization, and propagation, as well as the impact these phenomena have on the surrounding operational environment and force readiness.

Ice control capabilities could include, but are not limited to, the prevention of frostbite injuries, reduction of ice accretion on vehicles, vessels, and aircraft, decreased damage to infrastructure, maintaining aqueous solutions (potable water, medicines), solving transportation and logistics challenges (ice bridges, roads, runways), and enabling field operations.

The dynamic formation and dissolution of ice is a ubiquitous process with wide-ranging effects on
both natural and built environments, including creating structural challenges to both living and
non-living systems and materials due to the growth and expansion of ice crystals. To cope with
these challenges, organisms that inhabit environments prone to ice formation have evolved unique biological adaptations to mitigate, and in some instances exploit, the physical properties of ice in order to survive and flourish in harsh conditions. The ICE program seeks to utilize diverse and ingenious biological solutions to operating in extreme environmental conditions.

The Defense Advanced Research Projects Agency launched a four-year program in Sep 2022, that seeks to discover and optimize biologically sourced or inspired molecules that limit ice crystal growth, formation and adhesion to help develop technologies that could address operational challenges facing the Department of Defense in extreme cold environments.

Researchers under the three-phase Ice Control for cold Environments program will work with the U.S. Army Corps of Engineers Research and Development Center’s Cold Regions Research and Engineering Laboratory to test and assess candidate molecules, DARPA said Tuesday.

“Insects, fish, plants and freeze-tolerant organisms have evolved natural mechanisms to prevent ice formation and thrive in extreme cold,” said Anne Cheever, ICE program manager.

“These properties could be leveraged as part of the ICE program to develop persistent anti-icing coatings for surfaces and even produce specialized small molecules that work synergistically with biodegradable antifreeze proteins,” Cheever added

ICE program

Proposers may seek to leverage a series of technological advances across disparate fields that have
produced a confluence of biotechnology capabilities enabling the identification, engineering,
optimization, and scaling of new biologically sourced or inspired molecules displaying ice control
properties, including:
 ice-binding proteins (fish, insects, fungi, bacteria, and plants), capable of modulating the
physical and kinetic properties of ice formation in a dynamic fashion at the molecular level;
 pigments capable of absorption of defined wavelengths of light and radiative heat transfer
to selectively melt snow versus ice (algae and bacteria);
 cryoprotective polysaccharides (bacteria, algae, insects, and plants); and
 small molecule cryoprotectants and eutectic mixtures (animals, insects, and plants).

Although only a limited number of these compounds have been identified and experimentally
validated to date, these molecules hail from a diverse set of organisms and have demonstrated
unique functionalities by divergent mechanisms such as instigating ice formation at elevated
temperatures, decreasing ice formation at lower temperatures (with no effect on the melting point), selectively adhering to ice at ice/water interfaces, enabling cryoprotection and anti-desiccation activities.

ICE performers will characterize candidates based on their method of ice control, broadly grouped under inhibition, induction, and adhesion, regardless of the type of molecule (e.g., proteins, small molecules, polysaccharides). Some of the challenges to be addressed for each class of ice control molecule include, but are not limited to:
1) Discovering and characterizing new ice control molecules.
2) Measuring key physical properties of ice crystal formation and maturation and corresponding modulation by exogenous agents in standardized, quantitative, high throughput, and reproducible assays.
3) Optimizing function of ice control molecules at varied temperature ranges, improving stability, and enabling identification, isolation, validation, and optimization of novel molecules.
4) Improving the dynamic functional range of molecules to expand suitability for diverse DoD
applications.

The field lacks standardized, quantitative, and reproducible assays to measure key physical
properties of ice crystal formation and maturation, as well as their corresponding modulation by
exogenous agents. Current approaches are time consuming, require expert execution for reliable
results, can be dependent on qualitative observation/scoring, are low throughput, and can be prone to either false positive or negative results depending on method and protocol.

Standardized testing methodologies capable of robust, reproducible quantification of molecule
performance related to ice induction, adhesion and inhibition classes respectively, would be
advantageous to identifying and developing novel materials capable of inhibiting or accelerating
ice crystal formation/propagation or binding to ice for DoD ECW applications.

The ability to modulate specific properties of ice such as the type, size, shape, texture, freezing
point, melting point, kinetics, strength, and thickness would be advantageous for a wide variety of
DoD applications. Studies by a diverse cadre of investigators focused on elucidating the biochemical, and physiological adaptations that microbes, plants, and animals display to survive
extreme cold have identified a number of biological molecules (proteins, polysaccharides, and
small molecules) that exhibit the ability to modulate or exploit the properties of ice.

These activities include antifreeze, ice nucleation, ice recrystallization inhibition, ice structuring, and ice adhesion. While some ice-modulating molecules and their associated properties have been previously characterized and reported in literature, significant foundational research and development efforts are required to screen for activity in a robust, standardized, reproducible manner and to optimize molecules for performance. To systematically address these capability gaps, ICE program performers must sequentially develop solutions to expand discovery and standardize performance screening of molecules capable of inhibiting ice crystallization/re-crystallization, nucleation, and molecular adhesion to ice.

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