How a metal with a memory will shape our future on Mars

A rover on the Moon has metal wheels that can flex around rocky obstacles, then reshape back to their original form. On Earth, surgeons install tiny mesh tubes that can dilate a heart patient’s blood vessels all on their own, without mechanical inputs or any wires to help.

These shape-shifting capabilities are all thanks to a bizarre kind of metal called nitinol, a so-called shape-metal alloy that can be trained to remember its own shape. The decades-old material has become increasingly common in a wide range of everyday applications. And in the next decade, the metal will face its most challenging application yet: a sample return mission on Mars.

The temperature that triggers nitinol’s transformation varies depending on the fine-tuned ratio of nickel to titanium. Engineers can tweak the metal to adapt to a wide array of conditions, making it a key tool in places where complex mechanics won’t fit, like the blood vessels surrounding a human heart or a hinge that positions a solar panel by responding to the sun’s heat.

 

Article extracted from https://www.theverge.com/2021/3/17/22334611/nitinol-metal-shape-memory-alloy-mars-nasa