viết lại tiêu đề hay hơn bằng tiếng anh đảm bảo phải là tiếng anh bằng 1 dòng duy nhất và bỏ qua dấu “”

Researchers in Professor Stephanie Mueller’s group at MIT have spent much of the last decade developing a range of computational techniques aimed at rethinking how products and systems are designed. Just as platforms like Instagram allow users to edit 2D photos with filters, Mueller envisions a world where we can do the same for many physical objects.

In a newly published paper, her team at the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL) demonstrates a new printing technique in this direction called “thermochromomorph,” which creates images that change color when heated.

The researchers, led by lead author Ticha Melody Setapakdi SM ’22, a doctoral student in computer science and electrical engineering at MIT, say they can imagine their approach being applied in artistic and practical ways, such as in coffee cups that warn if the liquid is too hot, or packaging for perishable medicines and food that can indicate whether the product is being stored at a safe temperature.

So-called “thermochromic” materials, which change appearance with temperature, are not new; examples include consumer beverages like Coca-Cola and Coors Light, which are labeled “ready to drink” when chilled. But such examples in product marketing have traditionally been limited to a single color. By using inks with complementary properties — one set that changes from clear to color, and another that changes from color to clear — Sethapakdi says she and her colleagues “can finally leverage full-color printing processes, greatly expanding the design possibilities with thermochromic materials.”

The researchers worked with several visual artists to teach them how to use Thermochromomorph, soliciting feedback and brainstorming new narrative concepts and techniques that the tool could unlock, such as color-changing postcards that could tell sequential stories in a more compact and dynamic way. One participant also plans to use Thermochromomorph to create an educational science kit aimed at teaching students about color-changing sea creatures.

The researchers developed the technique specifically for use in “relief printing,” an early printing method in which a design is carved into a block of material, then painted with ink or pigments, and the image is transferred to paper or other surfaces.

Compared to techniques such as screen printing, relief printing is “lightweight” and requires less set-up and materials, allowing for faster, less risky, iterative work, Sethapakdi says. Artists such as Pablo Picasso and Salvador Dalí used a variety of related techniques, such as woodblock printing and linocut printing, in their work.

“Our key contribution is to apply these new materials to traditional artistic processes and explore how artists can use it as part of their practice,” said Sethapakdi, lead author of a related paper presented recently at SIGGRAPH Asia in Tokyo.

The color-changing components don’t necessarily have to come from an external, active source of heat or cooling, like a refrigerator or electric stove. Thermochromic inks, which have a lower activation temperature, allow for more subtle thermal changes triggered by human touch. Setapakdi says he could also imagine applying the new process to create interactive surfaces or similar “interfaces” that dynamically change visually when touched.

Thermochromomorph combines digital and analog processes in the form of CMYK imaging and laser cutting on the one hand, and manual printing and thermochromic inks on the other. The production involves four main steps:

1. Block Preparation: Thermochromomorph begins with a solid block of hardwood. The block is laser cut and engraved with the desired pattern, then washed with water to remove any remaining particles.
2. Inking the woodblock: First, a thin layer of ink is evenly applied to the woodblock using a rubber roller.The ink is then transferred from the roller to the wooden block.
3. Alignment: The woodblock is positioned using a locator to ensure the various ink layers are properly aligned, then the printing surface, such as paper, is placed over the wooden block and secured in place.
4. Printing an image: A printing press is used to apply even pressure to the printing surface to transfer the ink from the block to the surface. The hot image is printed first, then the cold image. (If necessary, the print can be corrected by applying additional ink to certain areas of the block.)

The three prints the team used to demonstrate its technique were a Batman comic book skeleton, a label depicting a fish and its underlying skeleton, and an image of a man seen from the side and the front. (In the next image, the viewing angle changes gradually as the temperature changes, creating the effect of movement.)

It should be noted that Thermochromomorph has potential limitations in terms of image resolution and print quality. Specifically, image resolution is limited by the smallest dot size the team’s laser cutter can engrave. Techniques such as screen printing can overcome this, but have the drawback of requiring more time and materials. In terms of print quality, pigments are not completely invisible even in their “transparent” state, so the clarity of the transfer depends on the thickness of the ink layer applied during printing. While this issue is specific to the properties of the pigments, Setapakdi said that in future iterations, the team plans to explore different image processing techniques to modify the overlay of halftone patterns in hot and cold images to mitigate these image artifacts.

Setapakdi and Mueller collaborated on the new paper with Juliana Covarrubias (Class of ’24), a graduate student in communication arts and sciences at MIT Paris-Myers, Tianyu Yu, a doctoral student at the University of California, Berkeley, and Mackenzie Leake, a research scientist at Adobe.