Switching it Up: Metals Change Material Properies at Will

Ever since the early days of alchemy, humans have been trying to manipulate the very nature of materials. We haven’t quite succeeded in turning lead into gold, but we have created some pretty interesting alloys. This one might be one of the most revolutionary of all time. A team of materials scientists at the Technical University of Hamburg and the Helmholtz Center Geesthacht have made an amazing new nanomaterial that is able to switch from hard and brittle to soft and malleable with nothing more than the flick of a switch.

The secret is actually quite simple: corrosion. When precious metals like platinum or gold are placed in an acidic solution, tiny pits and ducts are formed in the metal. The pores are filled with a conductive liquid such as saline solution, creating what the scientists call “a marriage of metal and water.” Ions are dissolved in the liquid which influence the metallic surface atoms. The catalyst to switch the material between hard and soft is electricity: varying charges can make the material super-strong (but more prone to breakage) or super-soft (but weaker). By changing its state along with the situation, the material could avoid serious damage or even heal itself. The ultimate goal is to create “intelligent” materials that can withstand all kinds of stresses – we just hope they don’t get too intelligent.

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See more in New Materials or under Science. June, 2011.