New material may revolutionise prosthetics, wearable technologies

Jerusalem: A team of researchers have developed new "metamaterials" that can solve problems like ill-fitting joint sockets, contact dermatitis and sebaceous cysts plaguing prosthetic patients for a long time.

Metamaterials are synthetic composite materials with structures and properties not usually found in natural materials -- that can be programmed to deform in a uniquely complex manner.

"We started with a series of flexible building blocks, or bricks, that had deformation properties that varied with their position," said Yair Shokef from Israel's Tel Aviv University. 

"The blocks were able to change their shape when we applied pressure. From there, we were able to develop a new design principle to enable these bricks to be oriented and assembled into a larger metamaterial with machine-like functionalities," he added.

The metamaterial has the unusual property that spatially-patterned compression in one direction leads to predictable spatially-patterned deformation (dents and protrusions) in other directions.

"A pattern of specific bulges appears when our seemingly normal cube is compressed," said Shokef, adding "Using metamaterials, we can 'programme' the material's behaviour by carefully designing its spatial structure.

The researchers calculated the number of possible stacks for different cubes of building blocks. They then developed a cube of 10x10x10 cm blocks on which a smiley face appears when the cube is compressed. This demonstrated that any given pattern can be produced on a cube's surface.

There are many applications on the horizon for this new research, published recently in the journal Nature. 

"This type of programmable 'machine material' could be ideal for prostheses or wearable technology in which a close fit with the body is important," Shokef said. 

"If we can make the building blocks even more complex or produce these from other materials, the possibilities really are endless," he added.

The breakthrough may also find future applications in soft robotics and wearable technologies.