Researchers have created a groundbreaking method that employs a specialized light projector along with a photosensitive chemical additive to embed two- and three-dimensional images within any type of polymer. This light-driven engraving remains within the polymer until it is exposed to heat or light, which erases the image, allowing the process to be repeated. This innovative technology is particularly useful in fields where having detailed visual data in a small, adaptable format is essential, such as in surgical planning and architectural design.
Researchers have developed a novel method using a specialized light projector and a photosensitive chemical additive to embed 2D and 3D images within various polymers. The engraving remains until heat or light is used to erase it, making the polymer ready for reuse. This technology is aimed at scenarios where having detailed, precise visual information in a compact and customizable format is vital, like planning for surgeries or designing buildings.
Imagine if doctors could capture three-dimensional images from medical scans and freeze them inside an acrylic block, creating a portable model of a patient’s heart, brain, kidneys, or other organs. After the consultation, a quick application of heat would erase the image, making the block ready for the next scan.
A recent article in the journal Chem from researchers at Dartmouth and Southern Methodist University (SMU) discusses a significant technical advancement that could facilitate such applications and more.
The study presents a method utilizing a specialized light projector to engrave both 2D and 3D images inside any polymer infused with a unique photosensitive chemical that the team created. The light-based engraving persists until heat is applied to erase the image, allowing for reuse.
In summary, the researchers say they “write with light and erase with heat or light,” according to Ivan Aprahamian, professor and chair of chemistry at Dartmouth and co-corresponding author of the paper. In trials, they achieved high-resolution images in polymers ranging from thin films to six inches thick.
This technology is designed for any situation where it is crucial to have detailed, accurate visual data in a small and customizable format, as noted by Aprahamian. Applications could include planning for surgeries, designing buildings, generating 3D images for educational use, and even artistic creation.
Aprahamian compares it to “3D printing that is reversible.” By using any polymer with optimal optical qualities—meaning it’s translucent—and adding their chemical switch, the polymer can function as a 3D display. This setup negates the need for virtual reality headsets or complicated equipment—only the correct plastic and the researchers’ technology are necessary.
Commonly available polymers, like an acrylic block, could be transformed into displays simply by incorporating the light-sensitive chemical switch developed by Aprahamian and Qingkai Qi, a postdoctoral researcher at Dartmouth and the study’s first author. This switch contains azobenzene, a compound that reacts to light, combined with boron difluoride to enhance its optical performance.
Once the switch has been integrated into a polymer, it reacts to red and blue light emitted from a projector created in the lab of Alex Lippert, a professor of chemistry at SMU and co-corresponding author of the study. The red light functions like ink, activating the chemical additive to form the image, while blue light serves to erase it, Aprahamian explains.
The projector casts light onto the treated polymer from various angles using different light patterns, as Lippert describes. The photosensitive chemical developed in Aprahamian’s lab responds where these patterns intersect, shaping 3D designs. Producing 3D images from 2D scans, such as a chest X-ray, would entail projecting slices of the original image into a polymer block or another form until all the slices amalgamate into a complete 3D depiction, Lippert states.
The researchers have successfully generated animated images in polymers, with ongoing work focused on refining the process. Meanwhile, the technology discussed in Chem could be adapted for practical applications in its current state for industry or healthcare.
“To scale this up, we need to adjust the properties of the chemical switch to enhance resolution, contrast, and refresh rate,” Lippert notes. “The projector system could theoretically be expanded and developed into a complete system with automated hardware and software for user-friendly implementation.”
