Engineering news
Spiders build structures from fine, but tough silk fibres. These fibres must properly attach to natural substrates, a surface on which an organism grows, such as a rock, and be compatible with their chemical and structural properties.
A team at the Macquarie University in Sydney, Australia, observed a “back-and-forth glue application” that yields robust silk attachments that are tough to break.
The scientists have dubbed this spinning mechanism of the arachnid nature's '3D printer' - and say mimicking it could enhance the performance of adhesive tapes and lead to better design of new composite materials.
“We have shown here, for the first time, how spiders achieve a tough bonding of their threads to flat, hydrophobic surfaces by a specific movement pattern of their spinnerets, the silk spinning organ of the spider,” says Jonas Wolff, lead author of the study.
The team used 3D-electron microscopy to reconstruct the structure of the silk attachment and spinning apparatus of the spider.
The silk attachment was pulled in different directions to measure the forces necessary to break the bonding, having no effect on the mechanical robustness.
“The way spiders rapidly and economically attach silk threads to unpredictable surfaces without any pre-modification is fascinating,” says Wolff. “One example of an application is the non-mechanical and instant attachment of cable-like objects to variable surfaces. We are currently looking for partners to put some of our ideas into practice.”
The University of Nottingham, which has developed antibiotic synthetic spider silk for applications such as drug delivery, regenerative medicine and wound healing, thinks such technology could pose benefits for its work.
“Being able to 3D print such materials – if the silk retains its biocompatibility – would allow the architecture of any scaffold to be more carefully controlled and hence could lead to the creation of larger scale and more complex tissue preparations using synthetic biology,” says Neil Thomas, professor of medicinal and biological chemistry at the university.
This article appears in the print March 2017 issue of PE magazine as "The secrets of spider web could lead to stronger glues"