Bubbles are lightweight, can be instantly created from minimal material, and their size can be controlled. In this paper, we propose BubbleFab, a fabrication method that enables rapid volumetric prototyping by dynamically generating and stacking plastic bubbles of varying sizes in real time. Using a custom design software, users can generate a stacking script from any 3D model, which is then executed by a robotic arm that autonomously extrudes and assembles the bubbles into a physical structure. The resulting objects are not only lightweight, but can also be reinforced after fabrication for use as molds. Furthermore, the materials used can be recovered and reused. We developed an end-to-end pipeline consisting of dedicated design software and fabrication hardware and evaluated the accuracy and durability of the generated bubbles. We also present a series of example outputs and application scenarios enabled by this method.

This paper introduces Sketched Reality, an approach that combines AR sketching and actuated tangible user interfaces (TUI) for bi-directional sketching interaction. Bi-directional sketching enables virtual sketches and physical objects to “affect” each other through physical actuation and digital computation. In the existing AR sketching, the relationship between virtual and physical worlds is only one-directional — while physical interaction can affect virtual sketches, virtual sketches have no return effect on the physical objects or environment. In contrast, bi-directional sketching interaction allows the seamless coupling between sketches and actuated TUIs. In this paper, we employ tabletop-size small robots (Sony Toio) and an iPad-based AR sketching tool to demonstrate the concept. In our system, virtual sketches drawn and simulated on an iPad (e.g., lines, walls, pendulums, and springs) can move, actuate, collide, and constrain physical Toio robots, as if virtual sketches and the physical objects exist in the same space through seamless coupling between AR and robot motion. This paper contributes a set of novel interactions and a design space of bi-directional AR sketching. We demonstrate a series of potential applications, such as tangible physics education, explorable mechanism, tangible gaming for children, and in-situ robot programming via sketching.

ExpandFab is a fabrication method for creating expanding objects using foam materials. The printed objects change their shape and volume, which is advantageous for reducing the printing time and transportation costs. For the fabrication of expanding objects, we investigated a basic principle of the expansion rate and developed materials by mixing a foam powder and elastic adhesive. Furthermore, we developed a fabrication method using the foam materials. A user can design expanded objects using our design software and sets the expansion areas on the surface. The software simulates and exports the 3d model into a three-dimensional (3D) printer. The 3D printer prints the expandable object by curing with ultraviolet light. Finally, the user heats the printed objects, and the objects expand to maximum approximately 2.7 times of their original size. ExpandFab allows users to prototype products that expand and morph into various shapes, such as objects changing from one shape to various shapes, and functional prototype with electronic components. In this paper, we describe the basic principle of this technique, implementation of the software and hardware, application examples, limitations and discussions, and future works.