Development of a new mechanical metamaterial holds the potential of revolutionising prosthetics and wearable technologies, researchers have revealed.
Some of the main problems with prosthetics are the ill-fitting joint sockets, contact dermatitis and sebaceous cysts and one of the reasons behind them being a problem is the pressure prosthetic devices place on the soft tissue of their bodies. Researchers at Tel Aviv University and their colleagues have developed a new way of manufacturing mechanical “metamaterials” that can be programmed to deform in a uniquely complex manner.
Researchers illustrated their approach through a three-dimensional printing of a metamaterial cube. A smiley-face pattern emerged on the side of the cube when it was compressed between custom-patterned surfaces. Researchers explain that to develop the new metamaterial, they first started off with a series of flexible building blocks that had deformation properties that varied with their position.
The blocks had the capability of changing their shapes as and when the pressure was applied. Using this as the base, researchers were able to develop a new design principle that helped them orient and assemble these bricks into a larger metamaterial with machine-like functionalities. 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. Researchers explain that they can ‘program’ the material’s behavior 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 centimeter 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.
“For each possible stack, the deformation within the cube results in a specific pattern on the sides of the cube,” said Dr. Yair Shokef of TAU’s School of Mechanical Engineering. “We can carefully combine the building blocks in a way that any desired pattern can appear on the sides of a compressed cube. We can also use the cube to analyze these patterns.”