Ocean-based bionic innovations

Bionics is a branch of science that integrates biology and technology. In bionic research, scientists and engineers examine natural laws, principles of structure and function of organisms, and apply their findings to the design of equipment, structures, and architecture. Leonardo da Vinci, a Renaissance genius who diligently examined nature and sketched plans for various flying machines, was one of the most prominent forefathers of bionics. However, the true development of this scientific subject was launched by John Keto, chief of the Aeronautical Systems Division, who formed a team in 1956 to investigate the possibility of utilising biological advances in technology.Jack Steele named the new field bionics two years later, in 1958. Since then, a plethora of equipment and technical solutions have been invented based on observations of the natural world. In this regard, not only the terrestrial but also the maritime environment is an inexhaustible source of knowledge.

Airborne sharkskin

Shark scales are undoubtedly a unique work of nature. They look like pointed discs with longitudinal ridges and grooves. That is why a shark stroked towards the tail is smooth, and in the opposite direction — rough. Its scales are so firmly attached to the skin that in ancient times it was used by humans as sandpaper to polish wooden objects. Shark skin was also used to cover the handles of samurai swords to give warriors a firm grip and prevent the weapon from slipping out of their hands. However, sharks do not wear their skin only for human benefit. Covering the body in scales with elongated furrows and grooves reduces water resistance more than perfectly smooth scales. In general, the swimming of a shark can be compared to sliding on ice on skates, and fish with flat scales to skiing. Apparently both methods of movement are good, but even on the most polished skis we will not make as agile and quick turns as on the narrow blades of skates.

The same is true for swimming in an aquatic environment. When an object moves quickly in water, smaller and larger turbulence of the fluid forms close to its body, making it difficult to swim efficiently. However, shark scales modify the flow of the fluid and make the vortices not form close to the skin, but a little further away, that is, on the protruding ribs of the scales. This makes the resistance of the liquid exerted on the swimming fish smaller. Therefore, the predator, like a skater, can cut through the water and cross the abysses of the sea more efficiently, and with the same expenditure of energy. In this respect, some shark species are exceptional sprinters. One of the fastest sharks is the shortfin mako, which can reach speeds of 70 km/h over short distances. Not much slower are white sharks, which can sometimes accelerate to 60 km/h.

As it turns out, shark skins were a great inspiration for engineers working on aircraft aerodynamics. Lufthansa technologists teamed up with BASF in 2019 to create a surface film called AeroSHARK. This artificial coating has microscopic ridges and grooves that mimic the structure of scales on shark skin. It was found that covering the aircraft surface with such a layer improves airflow, which reduces fuel consumption and thus CO2 emissions into the atmosphere. Lufthansa has estimated that covering all aircraft in the fleet with the innovative coating could save thousands of tons of fuel a year. Therefore, according to the carrier’s announcement, from 2022 it will cover all freighters of Boeing 777 type in foil imitating shark skin.

Humback propellers

The humpback whale, a cetacean that commonly inhabits the ocean, is also known as the longfin whale because its powerful pectoral fins are the longest of any whale species. They can reach up to 4.5 m in length in adult humpback whales. Thanks to its oars, despite its enormous weight and size (up to 45 t and 18 m long), the humpback whale can easily make turns, rotations and tight circles.

Scientists were intrigued by the grace with which this massive animal maneuvers in the water. They discovered that the secret lies precisely in the structure of the large pectoral fins. Along their front edge they are not smooth, but covered with numerous bulges and nodules. These irregularities make the streams of water flow around the surface of the fins extremely smoothly and without turbulence. Moreover, the fins can be tilted at a greater angle to the water flow before the whale comes to a stop than if they had smooth edges. Therefore, the nodular structure of the long lobes provides the humpback whale with effective lifting power, as well as stability and agility during underwater acrobatics.

This unusual discovery could find applications in the construction of both massive rotor blades and lightweight windmills. Canadian company WhalePower has invented and patented a wind turbine blade with spears on the edge. These are quieter than blades with smooth edges, and on top of that, they are more efficient because they harvest energy at lower wind speeds. The company also offers serrated fans for home fans and computers, which provide better air circulation compared to smooth blades. However, it is not the only company taking advantage of the humpback whale’s fin secret. Researchers at the German Aerospace Center have developed a special film with rubber balls that has been adapted to stick to the edges of helicopter main rotor blades. It reportedly makes the helicopter more stable and maneuverable during flight. It is possible that in the future the rotor blades of helicopters, hydrofoils or airplane wings will resemble the uneven fins of a humpback whale.

Sensitive sensors

In warm ocean waters, a species of crustacean, the clown fish, lives in the recesses of coral reefs. It has one of the most sophisticated visual systems of any animal in the world. Each eye can move independently, allowing a 360-degree range of vision without moving the head. Most impressive, however, is their ability to perceive their surroundings. Our eyes perceive a wealth of color through a combination of three colors: green, blue and red. We also see neither ultraviolet nor polarized light. The raptor, on the other hand, perceives up to 12 colors through its mosaic eyes composed of thousands of photoreceptors called ommatidia. In addition, it registers ultraviolet, infrared and even polarized light invisible to the human eye. These extraordinary abilities inspire scientists to create specialized cameras that will allow humans to see the unseen.

As it turns out, recreating the way a shrimp sees could bring significant medical advances. In 2021, a team of engineers at the University of Illinois Urbana-Champaign developed an image sensor capable of recording cancerous lesions. In laboratory tests on mice, the sensor made it possible to distinguish diseased tissue from healthy tissue in about 92% of cases. In addition, it made it possible to see the location and contour of changed tissues even when they were invisible to the naked eye. Therefore, the device would work well both in detecting early signs of disease and during surgery. A clear outline of the affected areas could assist the doctor in accurately removing even marginal parts of the cancer. Currently, despite treatments using advanced imaging devices and systems, some patients still undergo incomplete removal of their cancer, which often results in recurrence. Scientists are also working on creating miniature versions of cameras capable of integrating with endoscopic systems used in minimally invasive surgery. Therefore, it is possible that in the future modern mini-sensors will also become a part of smartphones. Thanks to a handy monitoring system, each of us could check whether any change on the skin does not require professional medical help.

Octopus manipulators

Octopuses are marine animals that can be easily recognized by the flexible arms that grow out of the visceral sac. Thanks to these arms, they are able to swim in water, walk on the bottom and grasp even smooth and slippery objects. This is facilitated by strong suction cups located on the underside of their arms. The agility with which the arms of these molluscs move inspired technologists to create flexible surgical manipulators. Thus, the European STIFF-FLOP project (STIFFness controllable Flexible and Learn-able manipulator for surgical OPerations) was born.

The aim was to create a soft manipulator, which will cut through the standard port of minimally invasive surgery (about 12–20 mm in diameter). This ambitious undertaking brought together 12 teams from seven countries Industrial Institute for Automation and Measurements, which participates in the project, presented a robotic arm with a gripper at the 2019 Hannover Messe. The innovative device, thanks to a hydrostatic system, efficiently bends, stretches and changes its stiffness, which can make it easier for the surgeon-operator to bypass healthy tissue and reach hard-to-reach regions of the body. Therefore, the soft tentacle gains an advantage over traditional endoscopes, which are limited in their ability to operate between delicate structures of the body due to the rigidity of metal components. Currently, work is underway to put this very promising invention into production. Perhaps the flexible arms of the manipulator will be improved and, for example, equipped with microscopic disks for precise cutting of diseased tissues or needles for stitching wounds that are difficult to access. Nature is a treasury of innovative solutions, so it is not unlikely that the idea to improve the bionic tentacles or other devices will come from the world of oceans.