Color-changing materials, such as photochromic pigments, allow objects to have reprogrammable multicolor surface images. Existing systems that reprogram these images are based on projectors and LEDs, each with advantages and limitations in device portability and image resolution. In this paper, we present ChromoLCD, a surface reprogrammer that uses a liquid crystal display (LCD) to achieve a compact handheld device without sacrificing image resolution. ChromoLCD consists of an LCD panel with a custom backlight containing R,G,B and UV LEDs, forming high-resolution light patterns with the required wavelengths. The compact form factor of ChromoLCD enables on-the-fly reprogramming of everyday surfaces. Our technical evaluation shows that ChromoLCD achieves a resolution of 25 ppi, which is 8 times better than the prior work. We demonstrate ChromoLCD with three applications, including the stamping of reprogrammable AR markers on a kitchen counter, on-the-fly designs on personal accessories, and reference pictures on a whiteboard.

CHI ’25, Yokohama, Japan

We print wax on the paper and turn the composite into a sequentially-controllable, moisture-triggered, rapidly-fabricated, and low-cost shape-changing interface. This technique relies on a sequential control method that harnesses two critical variables: gray levels and water amount. By integrating these variables within a bilayer structure, composed of a paper substrate and wax layer, we produce a diverse wax pattern using a solid inkjet printer. These patterns empower wax paper actuators with rapid control over sequential deformations, harnessing various bending degrees and response times, which helps to facilitate the potential of swift personal actuator customization. Our exploration encompasses the material mechanism, the sequential control method, fabrication procedures, primitive structures, and evaluations. Additionally, we introduce a user-friendly software tool for design and simulation. Lastly, we demonstrate our approach through applications across four domains: agricultural seeding, interactive toys and art, home decoration, and electrical control.