Abstract
While microgestures allow for subtle interaction, their application has largely focused on freehand input or static grasping. In this work, we present GraspUI, a comprehensive design space that treats the act of grasping as a multi-phase interaction journey. We identify seven distinct phases of grasping—from the initial reach and pre-grasp adjustment to the firm grasp and eventual release. For each phase, we propose object-centric microgestures that leverage the physical properties of the object being held. This approach enables a seamless transition between physical manipulation and digital control. We validate GraspUI through a user study exploring the intuitiveness and social acceptability of these gestures across various object categories. Our findings suggest that integrating gestures into the natural flow of grasping provides a more fluid and context-aware interface for ubiquitous computing environments.