Fly like a bird
From Greek mythology comes the tale of Icarus, son of Daedalus, who sought to escape King Minos by flying from the island of Crete with wings made of feathers held together by wax. Daedalus warned his son not to fly too close to the sun, but as boys often do, Icarus disregarded his father’s warning, the wax in his wings melted, and Icarus plunged into the sea and drowned.
Science has gone well beyond flapping wings made of feathers glued together, but now they are studying bird feathers to find out how birds fly. For example, the underside of a feather can capture air for lift, while the top of the feather can block air out when gravity needs to take over.
By 3D-printing structures that mimic the properties of feathers, the researchers found that the barbules—the small hook-like structures that connect feather barbs—are spaced within 8 to 16 micrometres of one another, suggesting that spacing is an essential property for flight.
From this research, scientists hope to engineer new materials for aerospace use.
Feather-like adhesives
And talking about feathers: have you noticed, if you run a hand along the barbs of a feather, the feather “unzips” itself, then almost miraculously pulls itself back together? Scientists are now looking into using this zipping mechanism of feathers as a model for new adhesives. The focus is on the barbules, to model an adhesive that could be stronger than velcro.
Photo credit: Irene Lasus/StockSnap
Sources
Sullivan, T.N., Meyers, M.A., and Arzt, E. (2019). Scaling of bird wings and feathers for efficient flight. Science Advances, 5(1) eaat4269. DOI: 10.1126/sciadv.aat4269.
University of California—San Diego. (2019, January 16). Feathers: Better than Velcro? Engineers detail bird feather properties that could lead to better adhesives (and aerospace materials). ScienceDaily. Retrieved 29 January 2019 from http://www.sciencedaily.com/releases/2019/01/190116150632.htm.
Oysters inspire new, stronger polymers
Oyster shells are a composite material with extraordinary mechanical properties, including high strength and resilience. Inspired by the shells, scientists have developed a technique to build composite materials that may improve the mechanical and potentially other physical properties of commercial plastic materials.
About 75 per cent of commercially used polymers is semicrystalline, with low mechanic strength.
The technique changes the crystallization speed of a polymer initially well mixed with nanoparticles, controlling how the nanoparticles self-assemble into structures at three very different lengths. This multiscale ordering can make the base material almost an order of magnitude stiffer, while retaining the desired deformability and lightweight behaviour of the polymeric materials.
These materials can be used in automobiles, protective coatings, food/beverage packaging, and even new materials and functional devices that can be used in structural applications such as buildings, but with the ability to monitor their health in situ.
Photo credit: pixabay
Sources
Columbia University School of Engineering and Applied Science. (2017, June 7). Oyster shells inspire new method to make superstrong, flexible polymers: Columbia Engineering technique could lead to stronger composite materials used in commercial products, opening the way for their use in structural applications. ScienceDaily. Retrieved January 29, 2019, from http://www.sciencedaily.com/releases/2017/06/170607085517.htm.
Zhao, D., Gimenez-Pinto, V., Jimenez, A.M., Zhao, L., et al. (2017). Tunable multiscale nanoparticle ordering by polymer crystallization. ACS Central Science. DOI: 10.1021/acscentsci.7b00157.
Elephant trunk as a model for robot hands
The elephant trunk can serve as a model for the design of robotic hands or grippers.
Elephants can pick up a variety of objects, varying in material and quantity, with their trunks. According to the researchers, it is difficult to develop a gripper that is flexible enough to pick up object ranging from a single pen, a pile of pens, carrot cubes, piles of wheat bran, or a cube of jelly (Jell-O).
Elephant trunks, which lack bones, form kinks or joints to compress small pieces of food into a bite-sized mass. The scientists are measuring the force an elephant applies to piles of food, and imaging the shape of the trunk when the elephant is grabbing various objects.
Data suggest that an elephant applies more force when attempting to pick up a pile of small particles. It seems counterintuitive for the elephant to put more weight on something it is trying to pick up, but when the elephant pushes down on the food, because the food is particulate, it is squeezed. The more tightly the food is compressed, the more likely it is that the friction between the particles will be enough to allow the elephant to pick it up.
Photo credit: Thomas Gehrke Elephant Noir via photopin (license)
Sources
Rochester Institute of Technology. (2018, October 24). Elephant trunks form joints to pick up small objects; research could translate to robotics. ScienceDaily. Retrieved January 29, 2019, from https://www.sciencedaily.com/releases/2018/10/181024163616.htm.
Wu, J., Zhao, Y, Zhang, Y., et al. (2018). Elephant trunks form joints to squeeze together small objects. Journal of the Royal Society Interface, 15(147). 20180377. DOI: 10.1098/rsif.2018.0377.
More on the science of nature
Nature is replete with examples of problems solved efficiently. More examples can be found in Natural inspiration, Natural inspiration 2, Natural inspiration 3, Natural inspiration 4, Natural inspiration 5, Natural inspiration 6, Natural inspiration 7, and Natural inspiration 8.