Physical and tangible representations of information have provided users with intuitive interactions in which users can control information through tangible controls using their hands. In these techniques, flexible materials have often been utilized. For example, clay has been used for an intuitive modeling tool which senses the shape of the clay and updates its 3D model data [Piper et al. 2002]. This example enables users to create 3D models without knowledge of computational methods for constructing 3D models. Though these tangible representations of information accept user input, they cannot provide bi-directional physical interactions since their physical properties are not controlled by computers. Therefore, it is difficult to represent dynamic changes of information using physical properties such as motion, size, and color. These tangible user interfaces employ static materials.