Monday, August 24, 2020

Artificial spider web gets an ionic boost

Amazing stuff!



"Spider silk has a tensile strength five times higher than that of steel, and its stretchable threads boast an adhesive coating that enables spiders to capture and trap prey in their webs. This adhesive coating does have a down side, however, which is that it attracts contaminants from the environment, causing the webs’ capturing efficiency to deteriorate."



"An artificial material with the same elastic, adhesive, self-cleaning, sensing and tensile properties as natural spider silk has been created by researchers in South Korea. ... Their method involves applying static electricity to fibre-like strands of an ionically conducting and stretchable organogel, which is a semi-solid material made of gelling molecules in an organic solvent (in this case, covalently cross-liked polyacrylamide chains in ethylene glycol with dissolved lithium chloride). The strands of this organogel are then encapsulated with silicone rubber and coated with a hydrophobic perfluorinated compound to reduce their surface energy (and thus surface tension).



The researchers ... wove these composite fibres into structures that resemble natural spider webs. They found they could make the web strands electro-adhere to target objects made from metals, ceramics and polymers, thanks to the static electric field that arises between adjacent web strands when a high voltage is applied."



Artificial spider web gets an ionic boost – Physics World

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