Learning from nature: optimized adhesives
As I discussed in a recent post at nanotechbuzz on Brian Eno’s talk, Before and After Darwin, nanotechnology can sometimes lead to insights into how nature works. Those lessons can then be applied to the design of new materials. Let’s look at a work in progress where scientists looking at nature at the nanoscale have made some discoveries that could transform whole industries.
Researchers from Northwestern University and the University of California, Santa Barbara have found an optimized adhesive contained in bone, abalone shells and spider silk that could be used in “glues” for nanocomposite materials such as carbon nanotubes and graphene sheets.
Researcher Paul Hansma said these optimized adhesives hold strong elements of materials together and yield just prior to the elements’ breaking points so as to prevent the entire structure from breaking. “Abalone shell and bone can heal themselves due to the weak bonds, such as hydrogen bonds or ionic bonds, that can reform,” he explained to PhysOrg.com.
In a paper published in the journal Nanotechnology, the research team draws these conclusions:
1. Nature is frugal with resources: it uses just a few per cent glue, by weight, to glue together composite materials.
2. Nature does not avoid voids.
3. Nature makes optimized glues with sacrificial bonds and hidden length.
Their observations of nature open the door to new insights into artificial glues and the promise of stronger, lighter, more efficient and economical adhesives. Thanks nature, for providing a valuable lesson, and thanks Dr. Hansma and company for unearthing it.
It couldn’t have been done without the nanotech tools to observe nature at the nanoscale, and I’m always delighted when I see scientists using these new tools to unlock nature’s secrets and show the way to new materials and products.
I hope the developers of new nano-based products will keep nature in mind and that we’ll see, for example, the discoveries described here lead to a new class of adhesives that far exceed current ones like urea formaldehyde, which is classified as a probable human carcinogen by the EPA.