We explore how a display surface can physically emerge on demand to support both mid-air visualization and direct touch interaction. We introduce blooming, a concept that repurposes Persistence-of-Vision (POV) motion to deploy a large, touchable surface from a compact, relocatable device. Using a soft, rotating line with arch-shaped electrodes, our system renders dynamic mid-air visuals while enabling direct touch input on the manifested surface. Realizing this concept requires addressing the unique challenges of touching spinning elements, including ensuring safety, minimizing disturbances to rotation caused by touch, and detecting brief unstable touches during spinning. We present a safety-oriented device design, special blades effective in minimizing finger disturbance, and optimization techniques tailored to transient, noisy touches. We also reveal how rotation speed and electrode height significantly affect sensing accuracy and user experience. Finally, we demonstrate applications that show how blooming touch displays can flexibly augment everyday objects and environments.
ACM CHI Conference on Human Factors in Computing Systems