We have often discussed metamaterials, materials whose function is decided by structure rather than composition. From doorknobs made out of one piece to material that bends sound waves, and from material that can turn from soft to stiff to material that shrinks when heated, the possibilities of metamaterials are endless. But what all these materials have in common is that they can only do one thing. So what if a material could contain multiple functions within its structure and could easily switch between them? Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences and the Wyss Institute of Biologically Inspired Engineering at Harvard University have developed a general framework to design reconfigurable metamaterials.
The research is based on the idea that simple geometries can be used as building blocks to form a new class of reconfigurable metamaterials.
By combining design and computational modeling, the team was able to identify a wide range of different arrangements and create a blueprint for building the materials in the future. The same models could also be used to quantify all the different ways the material can bend and how that affected the material properties.
Once a specific design was selected, the researchers constructed working prototypes for each metamaterial, using laser cutting and double-sided tape, as well as multimaterial 3D printing. The resulting structure can be folded along the edges to change shape, much like origami.
The next step in the research is to fabricate the metamaterial at a smaller scale. The design strategy is scale independent, meaning it can be applied to everything from metre-scale architectures to reconfigurable nano-scale systems.
The structures could be useful for structural and aerospace engineers, material scientists, physicists, robotic engineers, biomedical engineers, designers, and architects.
Images: Johannes Overvelde/Harvard SEAS