Molluscs hold key to tiny machines
Associate Professor David Macey from Murdoch's
biological sciences section reckons an unmanned version of the fantastic
voyage may be around the corner. That's why he is looking at chitons --
the primitive rock-eating mollusc found on rocks and reef all along WA's
coast. Why chitons?
"Their teeth are as hard as steel -- harder, in fact," said Professor Macey about the chitons that grind through rock as they eat the embedded algae. They have developed a coating of the harder-than-steel iron oxide magnetite on their teeth, similar to the way humans deposit enamel on their teeth.
Here's the key to the "fantasy" of tiny tools and machines.
"We're talking about nanotechnology -- the manufacture of tiny implements that can do super jobs, like gears for a tiny machine that could go round your blood stream cleaning plaque off the arteries," said Professor Macey.
He said we already had the technology to make tiny machines out of plastic, using photo-etching techniques. But we couldn't yet build anything so small out of a really hard material like steel. One possible way would be to build minute plastic "scaffolding" and then coat it with metal, although we hadn't developed the technology.
"However, chitons have been doing just that for millions of years," said Professor Macey.
Chitons develop a thin coating of a number of iron oxides on the organic substructure of their teeth.
Using a scanning electron microscope, Professor Macey and his research partners Ms Lesley Brooker, from Biology, and Professor John Webb and Alasdair Lee, from Chemistry, are studying how the chitons' teeth get their deposit of the shiny metal. The teeth are arranged in rows (between 40 and 120 rows) that grow forward -- the new ones replacing the metal-coated old ones as they are ground off at the front at a rate of a row every two days.
The researchers hope to identify all the elements being used and how the metal is gradually deposited on the teeth as they grow forward.
 |
| Close-up of chiton teeth. The shiny metal is an iron oxide. |
| Related articles | |
 |
$1 million grant for marine centre |
| Further information | |