As part of these new developments, humans are discovering inspiration in the works of art hidden in nature. Although Biomimetics has recently emerged as a scientific discipline, many researchers are already switching over to it. Biomimetics is the study of the design available with all its grandeur in nature and searching for ideal solutions to human problems. These solutions are then used to develop new technologies. Basically, it aims to make progress in technology by imitating the perfection of nature.

Many examples of what has been transferred from living things to technology, in fields as diverse as robotics, optics, new materials, vehicle technology, and so on, are now all around us. Yet, all engineering designs face a basic challenge: “ensuring the highest endurance with the least amount of material.” Spending less on materials will reduce overall costs, in both the long and short term. Lightweight materials mean saving money on energy over the lifetime of a project.

Thankfully, as Biomimeticians have discovered, nature is designed to be efficient.

Research into wheat stems has shown that they have remarkable characteristics when it comes to strength. Most of us have seen wheat fields waving in a wind strong enough to topple trees. Despite carrying a relatively heavy ear of grain and being supported by a delicate stem structure, the wheat is able to withstand strong winds. It rarely breaks.

This kind of strength could be an asset in building skyscrapers. While the ratio of the height of a wheat stalk to the base diameter is 500, the tallest building in the world, the 828-meter-high Burj Khalifa, has a height to width ratio of only 5. Wheat stems may hold the key to taller, stronger, more efficient buildings.

What are the physical and geometric reasons underlying the strength of wheat stems? Can these features be imitated to inspire new designs? Not only is the material used for great stability, but the geometric features and distribution of those materials have an important effect, too. The cross-sectional area of a characteristic wheat stem is shown in Figure 2.

When the cross-sectional area of the plant is examined, the following characteristics are seen: 1) The cross-sectional area is circular, cylindrical, and empty. 2) The filled wall section is similar to a honeycomb. 3) The density of the material increases gradually from the center to the outside, while the honeycombs formed by the hexagonal cells are shrinking in size. 4) The density of the material in the outermost periphery has increased greatly and the honeycomb structure has disappeared. 5) There are areas where the material is heavily piled up in the form of small circles near the outer wall.

When studying this design, an engineer will note a few things: 1) The hollow cylindrical structures increase the cross-sectional inertia and increase the flexural resistance. 2) The honeycomb structure is important for ensuring maximum durability using minimal material. Mathematicians have proved that a honeycomb structure can enable us to divide an area into small equal pieces with the shortest length of line. Just as in beehives, this structure exhibits the most efficient use of materials possible. 3) The increase in material density from the inner radius to the outer radius is intended to increase the cross-sectional inertia of the field in the cylinder and this increases flexural resistance. 4) It is also important, in terms of flexural resistance, that the material density at the outer wall rises to the highest level. 5) The circular small areas near the outer wall are similar to iron bars placed in cement. They increase the stiffness of the stem against bending. In fact, engineers have designed more robust bars, inspired by the geometry of the wheat stem (Figure 3).

In Figure 3, the dashed curve represents the actual measurements of the wheat stem and the parabolic continuous line represents the approximate curve calculated in accordance with the actual measurements. As can be seen in the figure, there is a slight decrease in material density in the inner wall. Then the density of the material making up the outer wall increases nearly 100%. The slight increase in the material inside the inner wall can be considered a kind of reinforcement to prevent damage to this small inner area. Based on this material density range, a new material for steel rods can be produced using a porous but simpler structure.

In Figure 4, we see a cross section of cylindrical rods that are filled, hollow, and inspired by wheat stems. According to the loading analyses done with the computer-based ANSYS program, it is observed that the newly designed rod had the lowest minimum stress and lowest maximum stress (Figure 5). This shows that in the new design, the stiffness decreases and the durability increases.

While studying nature, it is important to remember that nothing is pointless. Natural structures have been perfectly calibrated, and the scholars who know how to read them can create incredible works of art. A good analysis of nature’s perfection will enrich our minds and open the door to new inventions that will make our lives easier.

Reference

• Strength of Wheat and Barley stems and Design of New Beam/Columns, Mathematical and Computational Applications, 15 (1), 1-13, 2010.

With global climate change a serious threat to human existence, saving energy is of crucial importance. Air resistance – or “drag” – is the main force that causes fuel waste. The most important factor in drag is the “drag coefficient,” which is mostly dependent upon the shape of a given object. Objects whose shapes do not sharply contrast the air’s flow lines, and which render the changes in flow lines regular, have lower drag coefficients. In all creatures that move quickly through the air and water, their bodies are perfectly designed to keep their drag coefficients low. Unfortunately, research into these designs is just beginning. Scientists are just starting to study the geometries of certain creatures, in an effort to utilize their shapes to design more efficient vehicles.

The white, or Beluga, whale, has a perfect shape to facilitate its movements in water. Its beaky mouth and characteristic blunt head decrease drag, in spite of its bulky body.

In 1994, Airbus designed a cargo plane to carry very large cargos. As a cargo plane requires an ample interior, it also needs the right design to lower air resistance. In its design, Airbus imitated Beluga whales, which are both very large – and very aerodynamic. As such, the plane became known as the Airbus Beluga. In a major departure from normal plane design, a wider fuselage section, which resembles a bubble or hump, was added to the top of the Beluga. This extra space allows the plane to carry very large loads, such as helicopters, satellites, and plane wings. The plane, which weighs 86 tons when empty, has the capacity to carry loads up to 47 tons.

The Columbus Satellite, being sent from Germany to Nasa, in Florida.

The plane has been so successful that in order to meet increased demand, the company is planning to build a similar but larger plane, the Beluga XL.

The protuberances on the head and flips of a humpback whale.

In addition to the hump of the Beluga whale, designers have discovered that the rounded fins and heads of humpback whales provide a 10% decrease in drag, and a 5% increase in buoyancy (figure 4). They’ve incorporated these features into the design of next-generation helicopter blades. When a helicopter flies, the blade that spins forward is faster than the blade spinning backward. This situation causes the blade moving backward to temporarily lose lift. Together with turbulence, an extra load is brought to the rotor and the controlling rod, and this decreases the speed and maneuvering ability of the helicopter. In order to solve the problem, the back blade needs to be improved. Humpback whales inspired the solution. German aviation researchers placed 186 rubber protuberances, 6mm in width, on each blade. After good results from wind tunnel experiments, they made test flights and obtained recognizable enhancements in performance.

Thanks to the protuberances, the working angle of the propellers increased from 11 degrees to 17 degrees, and the performance increased 40% (figure 5).

Researchers witnessed a similar increase in performance when using the same principles for hydraulic wind turbines.

These are just a few examples of what seem like simple, overlooked qualities in nature that can actually inspire engineers, leading to major technological breakthroughs. We would all benefit from more scientists conducting research on this topic. The wondrous perfection of living creatures allows aircrafts – and our spirits – to soar to new heights.

When designing the next generation of planes, engineers would be wise to look to the sea, where whales offer up a perfect blueprint for decreasing drag and increasing performance.

References

• http://www.gizmag.com/humpback-whales-rotor-blades/21332/
• F. E. Fish, P. W. Weber, M. M. Murray, L. E. Howle, The Tubercles on Humpback Whales’ Flippers: Application of Bio-Inspired Technology, Integrative and Comparative Biology 51 (1), 203-213, 2011.
• T. Gruber, M. M. Murray, D. W. Fredriksson, Effect of Humpback Whale Inspired Tubercles on Marine Tidal Turbine Blades, ASME Paper No. IMECE2011-65436, 851-857, 2011, doi:10.1115/IMECE2011-65436

In recent years scientists have taken huge steps towards the bio-hybrid architecture developed for exploring an alternate approach to the control of autonomous robots (1). The plant-robot interactions through cyborg plants have been investigated in an effort to apply lessons from plants to robots, which provided another role for these organisms other than being a food source or decoration items. There are several joint experimental, numerical and robotic studies conducted in this newly developed area. One of the examples includes a flower robot made by Korean engineers which has the appearance of a common flower with petals, stem and leaves (2). The flower robot has sensing ability, moving mechanism, and home appliance function. It can recognize environmental conditions such as room temperature, pressure, voice and light intensity and can imitate the blooming of a flower, the bending of the stem and the stirring of the leaves in the wind. Other than these, the flower robot functions as a humidifier, a vision/voice recording system and an illumination device. For example, when flower robot receives light, it senses the intensity of the light and blooms. On the contrary, when it is dark, as the flower robot starts fading away and its illumination device turns on to flash the room.

Plantas nomadas, made by Mexican artist Gilberto Espaza, is another example of cyborg plants. It uses dirty water to live. It is a miniature eco-system consisting of plants and micro-organisms within a robotic shell. Each of the components symbiotically relies on the others: the plant provides the perfect environment for the microbe, and the microbe (in a microbial fuel cell) transforms nutrients in dirty water into energy to power the robotic components, and the robotic components provide mobility (3).

A team from Switzerland has been working on a project that endows a robot with the ability to react in response to environmental stress of a plant in order to maintain the state of the plant. The robotic devices monitor the changes in morphology and electrical activity of the avocado plants. According to these parameters, it classifies the drought level and triggers irrigation when necessary (4).

Some of the artists like James Stone, who is a Media Artist specializing in digital technologies and fabrication, are interested in seeing if plants are prone to act in certain ways, show preference and possibly display other traits such as emotion. Artists are specifically curious as to what would happen when a plant is augmented with technology but also given full control over such technology to do with it whatever it chooses (5). To see the results of such systems that provides a means for the plant to interact with people or things will surely be fascinating. A study in this line of research is done by a group of researchers in mobile robotics at ETH Zürich, whose long-term research goal is also to bestow machines with the ability to gain and employ knowledge from the universe to improve their intelligence, by building a prototype called iRobot Create. This cyborg plant consists of a computer running Linux, a normal plant and additional sensors and lives its own life, following its internal needs of water, sunlight and electrical energy (6). The cyborg stays away from obstacles using ultrasonic sensors, finds the best light spot using light sensors and goes to a recharge and to a mock-up water station using iRobot’s infrared sensor. Moreover, its sensors pick up noise caused by people moving around nearby, allowing cyborg plant to react by moving out of the way, to prevent themselves from getting underfoot (7).

It is very important to improve the ability of robots to work successfully in a complex and harsh environment, which would increase their usages. In one of those efforts exploring the use of biological systems to control robots under changing environmental conditions, Dr. David Hu and his group from Georgia Institute of Technology (8) used the Mexican jumping bean, Laspeyresia saltitans, which consists of an empty seed housing a moth larva. Heating by the sun stimulates movements by the larva which rolls, jumps and flips by the bean. They explored this unique means of rolling locomotion and recorded bean trajectories across a series of terrain types, including one-dimensional channels and planar surfaces of varying inclination by Time-lapse videography. They found that the shell encumbers the larva’s locomotion, decreasing its speed on flat surfaces by three-fold. Interestingly, they also showed that the two-dimensional search algorithm of the bean resembles the run-and-tumble search of bacteria. When they tested this search algorithm using both an agent-based simulation and a wheeled Scribbler robot, they demonstrated that the algorithm succeeds in propelling the robot away from regions of high temperature. It is amazing that from a study that involves a plant seed, a moth larva and a robot, scientists may develop applications in biomimetic micro-scale navigation systems.

The hi-tech devices that have been inspired by biological systems are not limited by the ones stimulated with plants. The insect world also represents a huge and original database for future bio-inspired systems, vehicles, and micro-vehicles (9). For example, the process of motion detection system in the fly’s eye is a good example of a neural circuit that was used for robot automatic piloting. Recently, a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats has been presented (10). Other than that, body undulation used by snakes and the physical structure of the body of a snake may offer major advantages over typical legged or wheeled locomotion designs in certain types of scenarios, therefore a large number of research groups have developed snake-inspired robots to make use of these benefits (11). Caenorhabditis elegans, a roundworm which has similar motions with snakes but with a simpler structure, was also selected to develop a small crawling robot with a thermal shape memory alloy, a homogeneous mixture or solid solution of two or more metal, as an actuator (a type of motor for moving or controlling a mechanism or system) due to the similarities of its properties to C. elegans muscles. (12).

Not only multicellular organisms but also unicellular (single-celled) organisms are utilized for generating cyborgs; for example, scientists used circuits prepared from Physarum polycephalum, amoeboid plasmodia of the slime mold, to control an omni-directional hexapod robot. Sensory signals from the macro-physical environment of the robot are transduced to cellular scale and processed using the unique micro-physical characteristics of intracellular information processing and the response from the cellular computation is amplified to yield a macroscopic output action in the environment mediated through the robot’s actuators(1).

In addition, a new biorobotic system using human neuroblastoma cultures was introduced in 2011 by a Spanish engineering group (13). Multielectrode Arrays Setups have been designed for direct culturing neural cells over silicon or glass substrates. The main objective of this work is to run a robot using this biological neuroprocessor and the final system could be used for many things such as testing how chemicals influence the behavior of the robot.

In summary, manipulation of robots that use living organisms as an interface to perceive the environment and transfer their responses into functions seem to have endless applications as well as challenges. Biologically-inspired technologies represent an emerging and promising field of interdisciplinary areas composed of engineering, computer sciences, chemistry, biology, physics and even art. In nature there are so many living and non-living elements designed by God to help us develop and improve robots to make our lives easier, better and more productive. Even a flower can offer us with something more than color and scent, and that is if we start thinking outside the box like so many people mentioned above have done.

Safiye Arslan is a Research fellow in the area of molecular biology in Nevada.

References

1. Tsuda, S., Zauner, K. P., & Gunji, Y. P. (2006). Robot Control: From Silicon Circuitry to Cells, Biologically Inspired Approaches to Advanced Information Technology (pp. 20-32). Osaka, Japan: Springer.

2. H. K. Park, S. H. Park, J. O. Park, (2007) “A study on the Moving Mechanism for Flower Robot,” International Conference on Control, Automation and Systems.

3. http://m.ammoth.us/blog/2010/09/a-cyborg-arboretum/

4. http://www.cyborgplant.com/

5. http://www.manofstone.com/cyborgplants/

6. Stocker, J., Veillat, A., Magnenat, S., Colas, F., Siegwart, R. (2011). Towards Adaptive Robotic Green Plants. TAROS 2011: 422-423

7. http://www.newscientist.com/article/mg21128305.900-robotassisted-plants-find-their-place-in-the-sun.html

8. West, D. M., Lal, I. K., Leamy, M. J., & Hu, D. L. (2012). Locomotion of Mexican jumping beans. Bioinspiration & Biomimetics, 7(3), 036014. doi:10.1088/1748-3182/7/3/036014

9. http://www.ercim.eu/EU-NSF/Bionics.pdf

10. Colorado, J., Barrientos, A., Rossi, C., & Parra, C. (2012). Inertial attitude control of a bat-like morphing-wing air vehicle. Bioinspiration & Biomimetics, 8(1), 016001. doi:10.1088/1748-3182/8/1/016001

11. Hopkins, J. K., Spranklin, B. W., & Gupta, S. K. (2009). A survey of snake-inspired robot designs. Bioinspiration & Biomimetics, 4(2), 021001. doi:10.1088/1748-3182/4/2/021001

12. Yuk, H., Kim, D., Lee, H., Jo, S., & Shin, J. H. (2011). Shape memory alloy-based small crawling robots inspired by C. elegans. Bioinspiration & Biomimetics, 6(4), 046002. doi:10.1088/1748-3182/6/4/046002

13. Ferrández, J. M., Lorente, V., de Santos, D., Cuadra, J. M., de la Paz, F., Alvarez, J. R., & Fernández, E. (2011). Human neuroblastoma cultures for biorobotics. Conference proceedings : … Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference, 2011, 6672-5. doi:10.1109/IEMBS.2011.6091645