A new type of 3D display could take the form of an acrylic cube with an image inside that can be easily erased and rewritten. The new technique could be used to make 2D, 3D, and even animated images.
The new display starts with a basic PDMS polymer that is treated with a chemical “switch” that makes it sensitive to light. The active ingredient in the switch is a compound called azobenzene, paired with boron difluoride to increase its response to light.
This chemical switch is activated when red light is shined on it, so an image can be etched into the polymer by reflecting it in red light. Blue light or a little heat can reset the image, allowing it to be easily rewritten.
The team tested this in a few different ways. Two-dimensional images can be drawn onto thin films of the engineered polymer fairly easily, as seen in the image of a dog above. But when projected onto a 6-inch (15-cm) thick cube, it becomes cooler—by reflecting light onto the cube from different angles, an image can be built up into 2-dimensional slices to create a 3-D image. The result is that an object appears suspended inside the cube. And again, hitting the cube with blue light or heat erases the image, ready for the next image.
Ivan Aprahamian
The researchers suggest that these rewritable, handheld 3D displays could find applications in architectural plans or even showing three-dimensional medical scans of organs or bones.
“This is like reversible 3D printing,” said Ivan Aprahamian, co-corresponding author of the study. “You can take any polymer with optimal optical properties—that is, translucent—and enhance it with our chemical switch. Now that polymer is a 3D display. You don’t need virtual reality headsets or complicated instruments. All you need is the right piece of plastic and our technology.”
Ivan Aprahamian
Even cooler, the team discovered that by projecting multiple 2D images into frames, they could animate 2D images in a 3D cube. When you rotate the cube, the image appears to move. It's an intriguing idea, and the researchers say it's only going to get better with more research.
“Scaling involves adjusting chemical key properties to improve resolution, contrast, and refresh rate,” said Alex Lippert, co-corresponding author of the study. “The projector system is in principle scalable and can be turned into a turnkey system with automated hardware and associated software for easy operation.”
The research was published in the journal Chemical.
Source: Dartmouth College