Weight-shifting mobiles: two-dimensional gravitational displays in mobile phones
In this paper, we present a novel actuation system for mo- bile phones: An actuated center of gravity. We present a number of applications, including interactive feedback, notification and the usage of the system as an ambient dis- play. We present the results of an initial user study, in which the users were asked to estimate the position of the device's center of gravity. The results indicated that weight-shift is suitable to support mobile interactions.