Holograms are a staple of science fiction, but the kinds of 3D, multicolored moving images floating in midair from movies like "Star Wars" are still a long way from reality. Now, though, researchers have developed the world’s first stretchable hologram, which could one day enable holographic animation, according to a new study.
In real life, holograms are more like paintings or photographs. They are effectively recordings of a 3D light field. When lit properly, they project a reproduction of the original object. Confusingly, the term refers to both the physical structure the image is recorded on as well as the resulting projection.
Almost all holograms contain a recording of just a single image, but now scientists at the University of Pennsylvania, in Philadelphia, have built a hologram on flexible polymer material that can hold several images. As the material is stretched, the different images are displayed one after the other, the researchers said.

But, this requires bulky optical equipment to be readjusted, and the hologram can only accommodate two images, the researchers said. The new hologram that Agarwal and his colleagues developed measured on the scale of a few micrometers and could only hold three images, but the only limit is its size, they said. (One micrometer is equivalent to one-thousandth of a millimeter.)