ChromaNails: Re-Programmable Multi-Colored High-Resolution On-Body Interfaces using Photochromic Nail Polish

We demonstrate ChromaNails, a physical nail reprogramming device that enables high-resolution multi-color textures on fngernails using photochromic nail polish for on-body interaction. Our ChromaNails reprogrammer uses a miniature RGB projector and a UV light source to project diferent wavelengths of light onto our photochromic nail polish. We create this nail polish by mixing cyan, magenta, and yellow (CMY) photochromic dye into a base substrate polish. This enables us to control the saturation and desaturation of the CMY particles inside our nail polish to various colors inside the CMY color space. Our integrated user interface enables laypeople to select their preferred color texture and adapts to various nail shapes. We demonstrate the usefulness of ChromaNails for on-body interaction through four application examples on reprogrammable fngernail QR codes, on-body calendars, security, and fashion.