SoylentNews

Phoenix666 [soylentnews.org] writes:

Imagine an aircraft that could alter its wing shape in midflight and, like a pelican, dive into the water before morphing into a submarine [futurity.org].

The key to making this Transformer-like fantasy a reality is a hybrid material featuring stiff metal and soft, porous rubber foam that combines the best properties of both: stiffness when it’s called for, and elasticity when a change of shape is required.

The material also has the ability to self-heal following damage.

“It’s sort of like us—we have a skeleton, plus soft muscles and skin,” says Rob Shepherd, a Cornell University engineering professor. “Unfortunately, that skeleton limits our ability to change shape—unlike an octopus, which does not have a skeleton.”
...
This hybrid material combines a soft alloy called Field’s metal with a porous silicone foam. In addition to its low melting point of 144 degrees Fahrenheit, Field’s metal was chosen because, unlike similar alloys, it contains no lead.
...
The elastomer foam is dipped into the molten metal, then placed in a vacuum so that the air in the foam’s pores is removed and replaced by the alloy. The foam had pore sizes of about 2 millimeters; that can be tuned to create a stiffer or a more flexible material.

In testing of its strength and elasticity, the material showed an ability to deform when heated above 144 degrees, regain rigidity when cooled, then return to its original shape and strength when reheated.

Original Study: Morphing Metal and Elastomer Bicontinuous Foams for Reversible Stiffness, Shape Memory, and Self-Healing Soft Machines [wiley.com].

Dunno about the aerodynamic vagaries of changing shape on the fly at speed, but it might be fun to re-tune the skin of a craft to reflect different wavelengths of light on demand.

Original Submission