The ancient 3D trick gives a special physical property

Researchers in the United States have discovered a new way to change the color of a material: by stretching it. They use ancient 3D technology for this.

Find out if your biceps want to grow a little by looking at a band around your upper arm? Putting a bandage on that it’s not too tight? A bathing suit that changes colors constantly while swimming? These materials with chameleon properties have come close thanks to research conducted at the Massachusetts Institute of Technology.

peacock feathers

Color is determined, as a rule, with paint or natural dyes. But it can also be done differently, explains biotechnologist Benjamin Miller, who drew inspiration from nature in his research. There is a phenomenon called browning. In addition, the reflection of light and therefore color is determined by the structure of the surface.

This phenomenon occurs in nature, among other things, in peacock feathers and butterflies, but it is difficult to imitate it. This is because the reflectance is largely determined at the nanoscale.

3D movie

However, Miller’s group has now succeeded in making a synthetic version of this substance. Earlier this week, the researchers published their findings in the scientific journal nature materials.

They began working with 3D films, which are included in passports, among other things. This material is two dimensional but it can refer to depth. The researchers glued it to a reflective surface and then, using light, printed images on it. Then the nanostructures were formed in the 3D film layer.

Lippmann process

This technology in itself is not new. Dating back to the late 19th century, it is known as the Lippmann process, which has a unique photographic feature that captures colors instantly without the use of dyes or filters.

When the print is ready, the film is released from the reflective material again and the film can then be processed into a flexible fabric. This flexibility is important: if you stretch the material or let it loosen backward, the surface nanostructure changes, and thus the color as well. This actually creates animated 3D images.

scalable

The advantage of this technology is that it is not very expensive, moreover, it is easily scalable.

The substance is already being tested in bandages. Nurses applying a bandage with this material can tell by color if they are applying the correct pressure. Researchers are also considering applications in robotics, for example.

Photos: MIT News

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