  We explore Calico, a miniature relocatable wearable system with fast and
precise locomotion for on-body interaction, actuation and sensing. Calico
consists of a two-wheel robot and an on-cloth track mechanism or "railway," on
which the robot travels. The robot is self-contained, small in size, and has
additional sensor expansion options. The track system allows the robot to move
along the user's body and reach any predetermined location. It also includes
rotational switches to enable complex routing options when diverging tracks are
presented. We report the design and implementation of Calico with a series of
technical evaluations for system performance. We then present a few application
scenarios, and user studies to understand the potential of Calico as a dance
trainer and also explore the qualitative perception of our scenarios to inform
future research in this space.
