Biomimetics—the study of the structure of biological substances to synthesize similar products by artificial mechanisms that mimic natural ones—is an old concept.1 For centuries, humans have sought to move and act like complex animal lifeforms. One even can find biomimetics in ancient Greek lore, as when Aphrodite and her son Eros slipped by the hydralike Typhon by disguising themselves and moving as fish. Literature and myth aside, though, in preindustrial society the mariner’s dream of biomimicry was unattainable. Oaken, sail-powered ships and steel-plated dreadnoughts, for instance, were slow-moving, unbendable, and coarse. They did not and could not replicate the stability of a sea turtle’s fin or the slipperiness of a dolphin’s skin to glide through seawater.
Until now. Physicists, engineers, computer scientists, and technologists can emulate animal biomechanics in physical experiments more closely than ever before. Building on eons of knowledge, the scientific community has commingled artificial machines, textiles, chemical compounds, and assorted alloys into recreating natural phenomena in the Information Age. In one recent example, a team of scientists and engineers at Pacific Northwest National Laboratory scattered networks of highly ordered synthetic, protein-like polymers onto a flat surface, replicating bone formation and healing found in nature. Numerous other laboratories have achieved similar feats, including the Massachusetts Institute of Technology’s Biomimetic Robotics Laboratory, which recreated animal motion and physiological traits in robots.
In the coming years, biomimetics will be game-changing for national security, despite not yet receiving the same attention as other emerging technologies, such as 5G, artificial intelligence (AI), or distributed cloud computing. To stay ahead of its competitors, therefore, the U.S. Navy must no longer confine ideas of a biomimetic fleet to science fiction.
Biomimetic technology will benefit future naval architecture and operations mostly in the critical areas of denial and deception, movement, and maneuver.
Denial and deception. U.S. adversaries depend on antiaccess/area denial strategies to fight where they believe U.S. forces are disadvantaged. For example, Iran has focused on building naval capabilities within the Persian Gulf region to assert control over the Strait of Hormuz (SOH), one of the world’s most important international chokepoints. At the same time, the ability to deceive enemies in denied, constrictive environments like the SOH is increasingly crucial for fulfilling U.S. naval operations. In this era of global, open-source ship tracking, widespread precision weaponry, and AI-powered targeting, the Navy’s conspicuous grey hulls could become as antiquated as steamships.
For these reasons, Navy platforms should, to the extent possible, take on the appearance of those denied environments—and the sea life within them—to evade detection. They must deny foreign penetration into U.S. operations and deceive the enemy at every turn. Fortunately, U.S. naval technologists have already planted the seeds of biomimetic camouflage with GhostSwimmer, an underwater Navy drone designed to look and swim like a surface shark. Yet GhostSwimmer only scratches the surface ahead of the coming era of fine-grained, deceptive warfare practices that biomimetics offers.
As this technology develops further—and if the Navy proactively pursues it—the possibilities for adaptation are relevant to Navy operations. The Navy could build air- or submarine-launched torpedoes or naval mines that look, act, and move more or less like sea urchins, starfish, or other invertebrates. So long as the vital components of these weapons systems, such as the fuses, detonators, and sensors, are left unchanged, they could be refitted with “smart, artificial squid skin” from electrically-activated molecules that can conform to the hues of the surrounding seascape—technology that materials scientists developed in 2015.
Consider, too, flexible, biomimetic shark skin—technology that has existed for approximately seven years—grafted onto small, autonomous underwater vehicles (AUV) made to resemble schools of fish, allowing for organic, hydrodynamic functionality. The AUV swarms could also carry adhesives that mimic the suckers on octopus arms for clasping onto the keels of enemy ships and deliver depth charges covertly or fulfill intelligence, surveillance, and reconnaissance missions while evading undersea detection systems.
Movement and maneuver. According to strategist Colin S. Gray, “the land can be occupied and fortified, as to a degree can earth orbit, but the sea and the air cannot be.”2 With great-power competitors making strides in hypersonic weaponry, long-range sensing and omnipresent satellite detection, and next-generation, high-end platforms, the Navy’s ability to dodge enemy strikes and achieve and hold positional advantage is more crucial than ever. Therefore, winning future wars may depend more on swiftness and agility than on traditional warfighting characteristics as firepower or mass.
Nature holds some keys for building a quicker, more agile navy. After billions of years of evolution, sea creatures are far better than man-made vessels at moving through the depths. They can turn, swim backward, and encircle threats on a dime, using relatively less kinetic energy than manned ships and submarines. For example, according to one engineering study, flapping foil, fin-powered propulsion systems in most fish are, overall, more efficient than conventional screw propellers on warships, which suffer efficiency losses due to wake. Sunfish are particularly nimble, rotating their outside fins to turn their bodies horizontally while fins closer to their center of mass direct forward thrust. Marine biologists have determined that eels can swim forward and backward using “traveling body waves” by increasing the midline flexions of their bodies. The arms on octopi, too, have a virtually unlimited, 360-degree field of movement, and can “bend, shorten, and elongate in a graded fashion at any point along their lengths.”3
Moreover, given most credible estimates, a multitude of ocean-dwelling species have yet to be discovered. Just this year, for instance, scientists discovered a new whale species, and they are constantly discovering new microorganisms and fish. With so many unknowns, the depths will supply a constant source of new inspiration and, potentially, future redesigns in fast weapons, countermeasures, or warships.
Recent laboratory successes portend a technological leap for future Navy biomimetic warships or submersibles. Those successes include the employment of fishlike robots designed with midlines that curve in a similar fashion as eels or the ability to glide through the water using four-joint propulsion mechanisms that allow for the same movements as fishtails.4,5,6 With scientists creating so many new materials—for example, newly-forged metal foam is 70 percent lighter than sheet metal, bendable, and can absorb 80 times more energy than steel—there is little reason to continue building warships with the same basic hull designs as before.7,8
Perhaps these inchoate technologies will one day challenge our very assumptions about the rigid-hulled fleet itself. A biomimetic naval fleet composed of newly discovered, flexible materials, such as borophene, that reproduces fishtail movements could prove quicker to react to danger than fleets adhering to old platform designs. In coming decades, then, America’s most sophisticated submarines may not rely on turbines at all. Instead, complex combinations of large, fin-powered tails, anguilliform hulls, and dorsal fins could propel them forward, evoking the movement of squid, octopi, eels, or sharks.
Policy Recommendations
To move forward with biomimetic hull designs and engineering into naval architecture, Navy leaders will need to:
Develop biomimetics-augmentation and platform-superiority strategies to meet and secure future warfighting needs.
Modernize world-class platforms at scale by integrating biomimetics into prototypes and existing concepts, perhaps by testing out concepts first in unmanned and small-scale platforms, and then expanding into even manned warships over a period of years.
Incorporate biomechanical engineers, materials scientists, and marine biologists who specialize in biomimetics into the Navy’s educational system—including the U.S. Naval Academy and Naval Postgraduate School—and its research and development efforts through the Office of Naval Research, which already runs a program devoted to “generating new materials from naturally occurring biological materials…and the design and fabrication of bio-inspired and biomimetic materials and devices.”
Overcome deep-set, Navy biases over how a modern naval force should look, move, or act.
Confer regularly with zoologists and biokinetic specialists on the discovery of new animal species—particularly in sea environments—and explore whether redesigned naval platforms could or should mimic their movements, and if so, how.
Innovation, especially for something as radical as biomimicry-enabled military technology, is time-consuming and pricey. The main obstacle, if this revolutionary technology advances, is to preserve and improve the Navy’s fighting edge over competitors that seek to constrain the operating environment for U.S. forces. In some areas, biomimetics will not apply to the Navy. Indeed, soft-hull ships might vitiate against their firepower, which is why engineers must continue to balance combat strength with maneuverability. Prototyping could show whether biomimetic upgrades are compatible with certain ship missions—or not. For example, destroyers and cruisers, whose missions include amphibious fire support or targeting inland enemies with long-range projectiles, exist to project power, not necessarily to conceal their presence. Good luck trying to hide a 6,900-ton warship, such as the Arleigh Burke-class destroyer, much less an aircraft carrier, with camouflage in a narrow chokepoint.
Embracing biomimetic technology will enhance the Navy’s ability to operate more efficiently and lethally. Faster, stealthier, more maneuverable, and more efficient ship and submarine designs will be enabled by closely studying and mimicking designs in nature. In the past, many U.S. Navy submarines have been named for creatures of the deep—Nautilus, Wahoo, and Sturgeon come to mind. Perhaps future Navy ships and submarines will resemble sea creatures in more than just name.
1. “Definition of biomimetics,” https://www.merriam-webster.com/dictionary/biomimetics.
2. Colin S. Gray, Strategy and History: Essays on Theory and Practice (Routledge, 2006: New York, NY), 149.
3. Scott L. Hooper, “Octopus Movement: Push Right, Go Left,” Current Biology 25, no. 9 (May 4, 2015): R366–68, https://doi.org/10.1016/j.cub.2015.02.066.
4.Deniz Korkmaz et al., “Dynamic Simulation Model of a Biomimetic Robotic Fish with Multi-Joint Propulsion Mechanism,” Transactions of the Institute of Measurement and Control 37, no. 5 (May 2015): 684–95, http://dx.doi.org/10.1177/0142331214565710.
5. John H. Long, Jr., “Maneuverability and Reverse Propulsion: How Eel-Like Fish Swim Forward and Backward Using Traveling Body Waves,” Office of Naval Research (1997). https://apps.dtic.mil/dtic/tr/fulltext/u2/a330550.pdf#page=122
6. Fengran Xie, “Central Pattern Generator Control of a Biomimetic Robot Fish for High Performance Swimming” (Ph.D., Hong Kong, The Chinese University of Hong Kong (Hong Kong), 2019), https://search.proquest.com/docview/2390781204/2F9F442AFE974667PQ/1.
7. Kate Groetzinger, “Researchers Have Invented a New Type of Metal That Pulverizes Bullets,” Quartz, https://qz.com/659130/researchers-have-invented-a-new-type-of-metal-that-pulverizes-bullets/.
8. “Metal Foam ‘Sandwich’ Is Bendy but Strong,” Futurity, July 16, 2015, https://www.futurity.org/foam-sandwich-961452/.