Researchers from the University of Rochester have created a new laser-etched metal that was inspired by diving bell spiders and rafts of fire ants. The team has created a metallic structure that is so water repellent that it won’t sink no matter how it is forced under the water or how much it is damaged. The new material has the potential to change many products.
The team thinks that the metal might one day lead to unsinkable ships, flotation devices that float no matter if they are punctured, and monitoring devices that can survive in the ocean long term. To create the metallic structure, the team used femtosecond bursts of lasers to etch the surface of metals with intricate micro and nanoscale patterns. These patterns trap air and make the surface of the metal superhydrophobic.
The scientists did find that after being immersed in water for long periods, the surfaced may start to lose its hydrophobic properties. The team says the key to the unsinkable design of the metal is the multifaceted superhydrophobic (SH) surfaces that trap a large volume of air. The team created a structure in the lab that has treated surfaced on two parallel aluminum plates that face inward, protecting them from external wear and abrasion.
The surfaces are just the right distance apart that they hold enough air to keep the device floating. They create a waterproof compartment with the SH surface preventing water from entering the compartment even if the structure is forced to submerge in water.
The team says that even after being forced to submerge in water for two months, the structures floated to the surface immediately when the load was removed. The structures also retained the ability to float after being punctured multiple times.