A new material may one day keep mussels off piers and boat hulls

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Shellfish stowaways on boat hulls could become castaways, thanks to a superslippery material.

Crowds of mussels can grab onto ships, piers and other infrastructure. They slow down the boats they commandeer, and they’re expensive to remove. The hitchhikers can even travel to new places and become invasive species (SN: 3/18/17, p. 30). A new lubricant-infused material could one day help prevent mussels from getting a grip in the first place, scientists report in the Aug. 18 Science.

Researchers modified a flexible silicone material to which Asian green mussels (Perna viridis) ordinarily stick liberally, suffusing it with a silicone lubricant. Some of the lubricant forms a thin, liquid layer and smooths out any microscopic roughness on the material’s surface; the rest creates a reservoir within the material’s pores. When the top layer wears off, the reservoir replenishes it.

Normally, mussels probe a surface with a footlike appendage and then send out a sticky thread to latch on. But mussels trying to attach to the lubricant-infused material either didn’t send out those threads at all or directed them to the wrong target — to the animals’ own shell or a different surface. That misfire suggests that the shellfish didn’t recognize the lubricated surface as a place to cling to, says study coauthor Joanna Aizenberg, an engineer at Harvard University.

She and colleagues are already commercializing lubricated coatings for use in other applications, such as implanted medical devices where it’s crucial that blood or bacteria not hold on to a surface. Next stop, the slippery coatings could take to the seas.