How mimetics at the nano scale are improving man made materials
We’re all familiar with the Biblical saying: “There’s nothing new under the sun.” The study of the ancient mechanisms of the brittle starfish led Technion scientists to the innovative secrets which would allow them to follow suit – creating ultra-tough ceramics.
An international research team led by Prof. Boaz Pokroy, Dr. Iryna Polishchuk, Dr. Alex Katsman Stas Kozachevich, and Yael Etinger-Geller at the Faculty of Materials Science and Engineering uncovered the unique protective mechanism of highly resistant lenses found in the Ophiocoma wendtii, a coral reef-dwelling brittle starfish. On the arms of this creature are hundreds of focal lenses that hold clues to making tough ceramics. Made of chalk, the lenses are powerful and accurate, and the deciphering of their crystalline and nanoscale structure has occupied lead researcher Prof. Boaz Pokroy and his team for over three years.
“Ophiocoma wendtii lenses are created in the open sea, not in a laboratory, and in effect we have discovered a strategy for making brittle material much more tough and durable under natural conditions,” said Pokroy. “It is ‘crystal engineering’ and tempering without heating and quenching – a process that could be very useful in materials science and engineering. Just as nature exhibits creativity in improving an organism’s abilities in various contexts such as strength, sensing, and self-defense, we see very high efficiency by the brittle star’s use of existing raw materials under natural conditions to create hardy and precise transparent lenses,” said Prof. Pokroy.
Scientists and engineers can now apply this biostrategy in toughening and strengthening synthetic ceramic materials utilized in various applications that span from optical lenses to automotive turbochargers and even biomaterial implants. The research was published in Science in December 2017.