“The firmness of a boiled egg can be adjusted at will through the cooking time. Some decisions are, however, irrevocable – a hard-boiled egg can never be reconverted into a soft-boiled one. There would be less annoyance at the breakfast table if we could simply switch back and forth between the different degrees of firmness of the egg.

Similar issues arise in the making of structural materials such as metals and alloys. The materials properties are set once and for all during production. This forces engineers to make compromises in the selection of the mechanical properties of a material. Greater strength is inevitably accompanied by increased brittleness and a reduction of the damage tolerance.”

Image courtesy Technical University of Hamburg and the Helmholtz Center Geesthacht

Jörg Weißmüller, a materials scientist at both the Technical University of Hamburg and the Helmholtz Center Geesthacht, and his team wondered if you could switch METALS back and forth between different degrees of firmness.  They placed precious metals (gold, platinum, what have you) in an acid bath. The acid corroded the metals, creating teensy tiny holes and channels all through the material, which they subsequently filled with a conductive liquid (dilute acid or saline solution).

Image courtesy Technical University of Hamburg and the Helmholtz Center Geesthacht

Ions dissolved in the conductive liquid influence the surface atoms of the metal, withdrawing or adding electrons to the metal’s surface atoms depending on the charge of the liquid.  Controlled changes in the atomic configuration can double the strength of the metallic materials, or make it weaker and more damage tolerant (Dillow).  The union of metal and water allows the researchers to alter the properties of the material at the touch of a button – an amazing breakthrough!

These “research findings could, for example, make future intelligent materials with the ability of self healing, smoothing out flaws autonomously….  Specific applications are still a matter for the future. However, researchers are already thinking ahead. In principle, the material can create electric signals spontaneously and selectively, so as to strengthen the matter in regions of local stress concentration. Damage, for instance in the form of cracks, could thereby be prevented or even healed. This has brought scientists a great step closer to their objective of ‘intelligent’ high performance materials.” (Source: Eurekalert). Not to mention it would make for a pretty sweet Iron Man suit… I’m just saying.

WU XING:
Filed under Metal and Water.

Cited:

Dillow, Clay. “New Nanometal Changes from Hard to Soft at the Flip of a Switch.” Popsci.com. 06/08/11. Accessed 06/09/11. URL.

“Hard or Soft: at the Touch of a Button.” Public release date: 6-Jun-2011. via Eurekalurt URL.