Origami Metamaterials | 17 Feb 2022

For Prelims: Origami Metamaterials, Metamaterials and its properties

For Mains: Achievements of Indians in Science & Technology

Researchers from Indian Institute of Technology Madras have developed such a material, called Origami metamaterials which could have many uses.

These combine the Japanese art of paper folding (origami) and the existing material of choice and fold it to obtain desired properties.

Researchers have developed a special class of origami metamaterials which show a constant value of Poisson Ratio when subjected to stress.
- When a material is crushed or stretched along a particular direction, it undergoes a modification in the perpendicular, or lateral, direction.
- The ratio between the deformation along the force and the deformation in a direction lateral to the force is called the Poisson ratio. The Poisson ratio can be positive or negative.
- In order to be useful, materials need to maintain a constant Poisson ratio when they crumble under pressure. However, they are prone not to do so, and the Poisson ratio varies as they deform.
The benefit is that the observed property does not depend on whether it is made from a sheet of paper, polymer or metal but under impact the sheet folds up along the creases.

Metamaterials are smart materials that have a wide range of properties and can be so different from each other that there isn’t a definition for them, although what they all have in common is that they are from an artificial origin.
This means that they aren’t found in nature and have been created by people.

Apart from their artificial origin, metamaterials are characterized because they have unusual electromagnetic properties, coming from their structure and arrangement and not from their composition.
This is similar to what happens with graphite, diamond and graphene, since they are all made of carbon, but due to their structure, they have very different properties.
One of the properties that can vary the metamaterials can be, for example, that the material has a negative refractive index.
- This makes these materials of great importance in optics and electromagnetism applications.

Potential Applications of Metamaterials include optical filtering, medical devices, remote aerospace operations, sensor detectors, solar power management, crowd control, radomes, antenna lenses, and even earthquake protection.
Lenses made of metamaterials may even enable imaging below the diffraction limit that prevents conventional optical lenses from magnifying any further.