When Nikola Tesla envisioned handheld devices that could showcase videos and photos, it probably felt like fiction. Fast forward nearly a century, and smartphones have become as essential as a second skin for many of us.
In a groundbreaking effort, digital fabrication engineers are expanding the potential of what everyday objects can do. A fascinating area of research involves creating reprogrammable surfaces—items we can digitally modify—to display crucial information and artistic designs on surfaces like walls, mugs, or even shoes.
Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), along with collaborators from the University of California, Berkeley, and Aarhus University, have made significant strides with their innovation, PortaChrome. This portable lighting system and design tool can transform the colors and textures of various objects. Equipped with ultraviolet (UV) and RGB (red, green, blue) LEDs, PortaChrome attaches to everyday items like shirts and headphones. Users can create designs and transmit them to the PortaChrome via Bluetooth, enabling surfaces to display colorful health metrics, entertainment graphics, or fashion statements.
In order to make an object reprogrammable, it must be treated with a photochromic dye, an invisible ink that responds to light patterns to reveal different colors. After coating the surface, users can manipulate patterns using the team’s graphic design software or directly interact with the device via an API to incorporate data-driven designs. When PortaChrome is affixed to a surface, its UV lights saturate the dye, while the RGB LEDs desaturate it—activating vibrant colors to align with the intended design.
According to lead author Yunyi Zhu, an MIT PhD student in electrical engineering and computer science, the integrated light system of PortaChrome changes colors in less than four minutes on average, which is eight times faster than their previous prototype, “Photo-Chromeleon.” This significant speed improvement is attributed to a direct light source that contacts the object rather than a projector that illuminates the surface.
“PortaChrome provides a more convenient way to reprogram your surroundings,” says Zhu. “Unlike our earlier projector-based system, PortaChrome is a portable fixture that can be placed directly on the photochromic surface. This facilitates color changes without requiring user involvement, while also minimizing UV exposure in the environment. For example, after a workout, users could literally wear a visualization of their heart rate on their shirt.”
Transforming Everyday Objects
During demonstrations, PortaChrome effectively showcased health data on various surfaces. For instance, a user who hiked with a PortaChrome device sewn into their backpack could transmit altitude and heart rate data to a design displayed on the back of their shirt, which had been coated with photochromic dye. The result was a dynamic health visualization created through a reprogramming script developed by the research team. In another demonstration, researchers illustrated a heart that gradually formed on the back of a tablet, depicting a user’s progress toward a fitness goal.
PortaChrome also excels in personalizing wearable devices. Researchers customized white headphones by applying blue lines and colorful stripes using the photochromic dye and then programming these designs through the PortaChrome system. This process transformed the headphones into a canvas reminiscent of watercolor art. Moreover, researchers even adjusted the color of a wrist splint to match various outfits with ease.
Ultimately, this research could usher in a new era of digitized personal belongings. Picture putting on a cloak that can instantly alter your shirt design, or using a car cover that redefines your vehicle’s appearance.
Components of PortaChrome
The PortaChrome device is constructed from four main components. It features a textile base as a supportive structure, a layer embedded with UV lights, another with RGB lights, and a silicone diffusion layer that softens and directs the light. This translucent silicone layer ensures individual pixels are beautifully illuminated across the design.
PortaChrome is designed to adapt to a variety of object shapes. For flat surfaces like tables, it can be laid on top, while its flexible nature allows it to wrap around curved items like thermoses, ensuring comprehensive reprogramming across entire surfaces.
This light system is not only portable but also easy to create using tools available in maker spaces (such as laser cutters). Its design can further be replicated using flexible PCB materials and mass-manufacturing techniques. Although PortaChrome can quickly transform surroundings into interactive displays, the team envisions even more improvements. For instance, they aim to integrate smaller LEDs, potentially allowing for instantaneous reprogramming of surfaces with higher-resolution designs due to increased light intensity.
“The surfaces of our everyday items transmit color and visual textures that convey essential information and influence our interactions with them,” observes Georgia Tech postdoc Tingyu Cheng, who did not participate in the research. “PortaChrome represents a remarkable leap forward by integrating flexible light sources (UV and RGB LEDs) with photochromic pigments into everyday objects, enabling dynamic displays that truly pixelate our environments. This innovation may revolutionize interactions within the realm of personalized fashion and adaptable user interfaces—laying the groundwork for real-time customization that seamlessly fits into daily life and offering a glimpse into the future of ‘ubiquitous displays.’”
Zhu’s research team includes nine CSAIL affiliates: Cedric Honnet, a PhD student at MIT Media Lab; former visiting undergraduates Yixiao Kang, Angelina J. Zheng, and Grace Tang; MIT undergraduate student Luca Musk; University of Michigan Assistant Professor Junyi Zhu; recent postdoc Michael Wessely from Aarhus University; and lead author Stefanie Mueller, the TIBCO Career Development Associate Professor in MIT’s Electrical Engineering and Computer Science and Mechanical Engineering departments, as well as the leader of the HCI Engineering Group at CSAIL.
This research received support from the MIT-GIST Joint Research Program and was showcased at the ACM Symposium on User Interface Software and Technology in October.
Photo credit & article inspired by: Massachusetts Institute of Technology
