The development and widespread use of digital fabrication techniques has accelerated the fabrication of three-dimensional (3D) objects, enabling not only to design their shapes but also to customize their internal structures and materials to realize various functions. In this research we propose a novel design method to embed internal pumps and liquid paths inside 3D objects. We utilized a pump driven by electrohydrodynamics (EHD) of fluid migrating in response to an applied electric field. To arrange the EHD pumps and fluid paths in appropriate positions inside 3D objects, we stacked layered acrylic plates cut with digital fabrication tools such as laser cutters and cutting plotters. Using these embedded pumps, we can control the flow of fluid to change color, shape, and motion of the objects. In this paper, we detailed our fabrication techniques named LayerPump, and demonstrated its design space and application scenarios.

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.

We introduce MorphIO, entirely soft sensing and actuation modules for programming by demonstration of soft robots and shape-changing interfaces.MorphIO's hardware consists of a soft pneumatic actuator containing a conductive sponge sensor.This allows both input and output of three-dimensional deformation of a soft material.Leveraging this capability, MorphIO enables a user to record and later playback physical motion of programmable shape-changing materials.In addition, the modular design of MorphIO's unit allows the user to construct various shapes and topologies through magnetic connection.We demonstrate several application scenarios, including tangible character animation, locomotion experiment of a soft robot, and prototyping tools for animated soft objects.Our user study with six participants confirms the benefits of MorphIO, as compared to the existing programming paradigm.

Here we report the new soft sensor "FoamSense" that can measure the deformation state of a volumetric soft object such as compressed, bent, twisted and sheared (Figure 1). This sensor is made by impregnating a porous soft object with conductive ink. The design process of FoamSense is explained. We then summarized the features and basic characteristics of some porous materials for designing these sensors appropriately. We also proposed the potential of using digital fabrication for controlling the carrier structure of FoamSense. Proposed porous structure showed an anisotropic sensor characteristic. We discussed the potential and limitation of this approach. Three possible applications are proposed by using FoamSense. FoamSense supports a richer interaction between the user and soft objects.

In this paper we discuss the development of a novel rapid prototyping method that makes the process of creating tangible electronic artifacts faster and easier. This method makes use of a new paper-like material that can be given any form just by hand or by using other stationary objects. This material changes its stiffness and becomes harder soon after the modeling process. Furthermore, this material can be integrated within electronic circuits using magnetic connectors and silver. The discussed method has been conceptualized using a People-Centered Design approach while its implementation has been led by an engineering approach. Both, the conceptualization process as well as the implementation of the discussed rapid prototyping method have been detailed in this paper along with example scenarios where the said implementation could be useful.

In our previous studies, we succeeded in construction self-oscillating gel actuator such as a self-walking gel and a dynamic motion of a gel actuator. However, the speed of the swelling-deswelling self-oscillation is too slow in order to realize practical chemical robot. In this study, we succeeded in the wide-range control of the period for the swelling-deswelling self-oscillation of a novel polymer gel by selection of the initial concentration of the Belouzov-Zhabotinsky (BZ) substrates and the temperature. The novel polymer gel was composed of a non-thermoresponsive and biocompatible poly-vinylpyrrolidone (PVP) main chain covalently-bonded to the ruthenium catalyst for the BZ reaction. Moreover, we clarified the influence of the initial concentration of the BZ substrates and the temperature on the period and the self-oscillating behavior. By optimizing the initial concentration of the BZ substrates, we cause the swelling-deswelling self-oscillation in 0.5 Hz. The maximum frequency (0.5 Hz) of the novel gel was 20 times higher than that of the conventional-type self-oscillating gel. Moreover, we showed that the displacement of the self-oscillation for the gel has a trade-off relationship against the frequency of the self-oscillation.