Brittle Starfish Make Tough Ceramics

An international research team led by the Department of Materials Science and Engineering at the Technion-Israel Institute of Technology has discovered how a beautiful, brainless brittle star can create material similar to tempered glass underwater at ambient conditions. The findings, published in the December 8 issue of Science, may open new bio-inspired routes for toughening brittle ceramics in various applications.

The researchers uncovered the unique protective mechanism of highly resistant lenses located on the arms of 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 Professor Boaz Pokroy and his team for the past three years.

Prof. Pokroy researches materials created by living organisms, and produces analogous synthetic materials using methods inspired by nature. Mollusk shells, pearls, bones, and turtle shells are some examples of biominerals – minerals produced by the creature itself.

“What is impressive about biominerals is that they are made from materials available to the organism, for example, chalk,” said Prof. Pokroy. “Engineers would never choose chalk as a durable building material, but nature does, and successfully, using different toughening and strengthening strategies. Moreover, the creatures produce these biominerals under available conditions, without furnaces and pressure-generating devices available in research laboratories. It is therefore clear that, as scientists and engineers, there is much for us to learn from these processes.”

Continue reading at Technion (Israel Institute of Technology)

Image via Technion