Harvard researchers design tunable 3D material

Harvard researchers have designed a new type of foldable material that is versatile, tunable, self-actuated and can change size, volume and shape and can be used as a portable shelter.

It can fold flat to withstand the weight of an elephant without breaking and pop right back up to prepare for the next task.

The research, published in journal Nature Communications, said the structure is inspired by an origami technique called snapology and is made from extruded cubes with 24 faces and 36 edges.

"We have designed a three-dimensional, thin-walled structure that can be used to make foldable and re-programmable objects of arbitrary architecture, whose shape, volume and stiffness can be dramatically altered and continuously tuned and controlled," Johannes T. B. Overvelde, first author of the paper, said.

Like origami, the cube can be folded along its edges to change shape. The team embedded pneumatic actuators into the structure, which can be programmed to deform specific hinges, changing the cube's shape and size, and removing the need for external input.

The team connected 64 of these individual cells to create a 4x4x4 cube that can grow, and shrink, change its shape globally, change the orientation of its microstructure and fold completely flat.

As the structure changes shape, it also changes stiffness -- meaning one could make a material that is very pliable or very stiff using the same design. These actuated changes in material properties adds a fourth dimension to the material.

The material can be embedded with any kind of actuator, including thermal, dielectric or even water.