Dr Mickey Huson at a CSIRO laboratory with the atomic force microscope.
Resilin project clocks near perfect 98 per cent
The resilience of a super-elastic protein found in insects exceeds the bounciness of all other known rubbery materials.
12 September 2008 | Updated 14 October 2011
Highly resilient, rubbery materials have many potential commercial and medical uses. One of the most exciting such materials is the natural protein resilin, found in insect flight muscles.
When CSIRO researchers began making a genetically engineered form of resilin, they had no way of accurately measuring its resilience. The quantities they could make were too small for use in conventional instruments.
At the time, Dr Mickey Huson and Dr Jane Maxwell (now retired) were investigating the nano-scale mechanical properties of wool and gelatine, using an atomic force microscope.
They speculated that the unique capabilities of the atomic force microscope might be able to measure resilience, even though such measurements had not been made before.
Starting with samples of readily available synthetic polymers, the researchers found that the atomic force microscope reliably reproduced resilience values already established for these materials.
Would the technique also work on the genetically engineered (GE) resilin? Here the technical problems intensified. For example, the first samples of GE resilin were shapeless and soft — little more than blobs of jelly.
Nevertheless, after overcoming these difficulties the researchers were able to record unusually high values for resilience of more than 90 per cent.
Dr Huson and Dr Maxwell then applied their skills to natural resilin in a tendon from a dragonfly’s wing, recording a resilience of 92 per cent.
'This confirmation that CSIRO’s GE resilin had properties similar to natural resilin was a big boost to our confidence,' says Dr Huson.
Larger samples tested
As resilin production methods improved, the samples grew larger and were more easily handled. They could be cast into defined shapes such as strips and rods, which Dr Huson was able to analyse with conventional tensile testing instruments.
These tests confirmed extraordinary resilience values of 98 per cent, and also yielded data on other vital physical properties.
“This confirmation that CSIRO’s pro-resilin had properties similar to natural resilin was a big boost to our confidence.”
Dr Mickey Huson
Dr Huson’s current research is providing insights into the properties and structure of GE resilin, to assist in the production of materials for specific applications.
Resilin has a near-perfect capacity to recover, or ‘bounce back’, after stress is applied and great durability. It might be used:
as a high-efficiency rubber in industry
in spinal disc implants
in artificial blood vessels,
perhaps even to add extra spring to the heels of running shoes.
About the scientists
Dr Huson is a physicist who investigates the structure and properties of polymers.
Dr Maxwell was an expert in the use of the atomic force microscope. She has since left the Division and Nicole Phair-Sorensen now undertakes this role.
Dr Chris Elvin of CSIRO Livestock Industries leads the resilin project, which emerged from his bio-nanotechnology research.
Other key collaborators include the University of Queensland in Brisbane, Monash University in Melbourne and the Australian National University in Canberra.
Read CSIRO's Rubber from resilin research paper.