Shapeshifting aircraft could be possible with new alloy that stretches 20 times

A highly flexible alloy made of metals titanium and nickel by researchers at the National Institute of Materials Science in Japan could be the critical component needed to make shape-shifting aircraft or super strong artificial muscles.

The alloy has the strength of steel but can stretch like rubber when environmental conditions are changed.

Shape-shifting aircraft are still a concept found in science fiction because scientists have struggled to develop a material that is flexible enough to achieve the shape-shifting effect and strong enough to withstand the rigors of flying.

There is always a trade-off when balancing strength and flexibility. One is achieved at the cost of the other. While a flexible, shape-shifting aircraft can deliver benefits for higher energy efficiency and faster transportation, these cannot be achieved by risking the safety of the passengers using a material that lacks proper strength.

Researchers at the National Institute of Materials Science (NIMS) in Japan may have just found a way to achieve both strength and flexibility in a material without making any sacrifices on either.

Titanium Nickel Alloy

Previous research in this area has identified that an alloy made from titanium and nickel has special properties, like stretching to limits far higher than those of other metallic alloys while keeping its new form. When the alloy’s temperature is increased, it can also return to its original form.

While this makes the alloy a great candidate for building a shape-shifting aircraft, the hurdle that researchers faced in using it was the limitations when the alloy displayed these characteristics.

The material, however strong and flexible, only displayed these characteristics at specific temperatures, severely limiting its applications. A research team led by Xiaobing Ren, a professor at NIMS, devised a three-step procedure to make the alloy display these characteristics across a wide range of temperatures.

The three-step procedure

The researchers first deformed the alloy and elongated it by over 50 percent, then heated it to 572 Fahrenheit (300 degrees Centigrade) before elongating it once again.

In the final step, the researchers elongated the alloy by only 12 percent, but by the end of the process, the material became capable of withstanding pressure about 18,000 times greater than normal atmospheric pressure, making its strength performance comparable to steel while also being 20 times more flexible than the commonly used alloy.

More importantly, the titanium-nickel alloy now demonstrated this behavior across a wide temperature range of minus 112 Fahrenheit to 176 Fahrenheit (minus 80 degrees to 80 degrees Celsius).

Speaking to New Scientist , Ren explained that the alloy displayed these properties because it behaved more like glass than like metal. Compared to conventional glass, however, the alloy has areas that have “seeds” of deformation.

In simple terms, the alloy has areas where molecules are arranged in such a manner that they support the material’s deformation instead of breaking. The absence of such seeds of deformation in glass makes it brittle, while its presence makes this material highly flexible.

Since the method of developing the material is straightforward, it can be easily replicated in other labs and is also suited for large-scale industrial adoption. With this research, work on making shape-shifting aircraft can finally begin.

The research studies were published in the journal Nature .