Diving spiders and fire ants inspired US researchers to build a metal structure that is water repellant, and refuses to sink, even when punctured, which qualifies it to be used in many applications such as manufacturing unsinkable ships.
Red and brown fire ants can survive for weeks floating until they dock on dry ground and continue their lives, while water spiders spend their entire life in river and pond water without reaching the surface to breathe air.
The spiders and fire ants can survive long periods under or on the surface of water by trapping air in an enclosed area. Aquatic spiders, for example, create an underwater dome-shaped web, a so-called diving bell that they fill with air carried from the surface between their legs and abdomens. Similarly, fire ants can form a raft by trapping air among their bodies.
In their study published in the ACS Applied Materials and Interfaces journal, the researchers simulated the natural powers of ants and spiders, by creating a multi-layer structure that can trap huge amounts of air.
Chunlei Guo, professor of optics and physics, and head of the research team, said in a report published on the University of Rochester's website: "The structure uses a groundbreaking technique the lab developed for using femtosecond bursts of lasers to etch the surfaces of metals that trap air.
Then, the surfaces are placed on two parallel aluminum plates face inward, not outward, so they are enclosed and free from external wear and abrasion.
The surfaces are separated by just the right distance to trap and hold enough air, creating a waterproof compartment."
Even after being forced to submerge for two months, the structures immediately bounced back to the surface after the load was released. The structures also retained this ability even after being punctured multiple times.