Inflatable systems have been attracting attention in the field of interaction design. Conventional tabletop-sized pneumatic systems tend to be complex because they require bulky and noisy equipment. Therefore, several liquid-to-gas phase change actuators that use vaporization have been proposed. But these actuators have problems with controllability, reusability, and reconfigurability. In this study, we propose InflatableMod, novel inflatable modules based on the efficient control of liquid-to-gas phase change actuators. These are designed with a compact circuit that has a liquid transfer function to feed the required amount of low-boiling-point liquid into the pouch and a heating function to inflate the pouch by the volume change. This approach allows for a compact, silent, and untethered inflatable system. It is also possible to create an untethered and reconfigurable multi-inflatable system because each module is synchronized. In this paper, we propose the design of the modules, evaluate their performance, and present application scenarios.

Physical interfaces that change appearance by controlling transparency have attracted attention for wide applicability. However, many existing methods are limited to planar objects, and it is difficult to control transparency in three-dimensional objects and to control transparency continuously. In this study, we propose a novel method to control the transparency of three-dimensional objects by utilizing the mechanical emulsification phenomenon of liquid. This approach is to fill the object with two transparent liquids that are liquid-liquid phase separated and agitate the liquids inside the object to make them cloudy and control their transparency. By using electrohydrodynamic (EHD) pumps, which can be freely positioned inside the object, to agitate the liquid, it is possible to control the transparency of complex three-dimensional objects. Continuous control is also achieved by changing the ratio of the two liquids. In this paper, we describe the details of proposed method for controlling the transparency and show application scenarios.

In recent years, actuators that handle fluids such as gases and liquids have been attracting attention for their applications in soft robots and shape-changing interfaces. In the field of HCI, there have been various inflatable prototyping tools that utilize air control, however, very few tools for liquid control have been developed. In this study, we propose HydroMod, new constructive modules that can easily generate liquid flow and programmatically control liquid flow, with the aim of lowering the barrier to entry for prototyping with liquids. HydroMod consists of palm-sized small modules, which can generate liquid flow with the electrohydrodynamics (EHD) phenomenon by simply connecting the modules. Moreover, users can configure and control the flow path by simply recombining the modules. In this paper, we propose the design of the modules, evaluate the performance of HydroMod as a fluid system, and also show the possible application scenarios of fluid prototyping using this system.

Designing and manufacturing actuators using soft materials are among the most important subjects for future robotics. In nature, animals made by soft tissues such as the octopus have attracted the attention of the robotics community in the last years. Suckers (or suction cups) are one of the most important and peculiar organs of the octopus body, giving it the ability to apply high forces on the external environment. The integration of suction cups in soft robots can enhance their ability to manipulate objects and interact with the environment similarly to what the octopus does. However, artificial suction cups are currently actuated using fluid pressure so most of them require external compressors, which will greatly increase the size of the soft robot. In this work, we proposed the use of the ElectroHydroDynamics (EHD) principle to actuate a suction cup. EHD is a fluidic phenomenon coupled with electrochemical reaction that can induce pressure through the application of a high-intensity electric field. We succeeded in developing a suction cup driven by EHD keeping the whole structure extremely simple, fabricated by using a 3D printer and a cutting plotter. We can control the adhesion of the suction cup by controlling the direction of the fluidic flow in our EHD pump. Thanks to a symmetrical arrangement of the electrodes, composed by plates parallel to the direction of the channel, we can change the direction of the flow by changing the sign of the applied voltage. We obtained the pressure of 643 Pa in one unit of EHD pump and pressure of 1428 Pa in five units of EHD pump applying 6 kV. The suction cup actuator was able to hold and release a 2.86 g piece of paper. We propose the soft actuator driven by the EHD pump, and expand the possibility to miniaturize the size of soft robots.

Much attention has recently been given to a printing method because they are easily designable, have a low cost, and can be mass produced. Numerous electronic devices are fabricated using printing methods because of these advantages. In paper mechatronics, attempts have been made to fabricate robots by printing on paper substrates. The robots are given structures through self-folding and functions using printed actuators. We developed a new system and device to fabricate more sophisticated printed robots. First, we successfully fabricated complex self-folding structures by applying an automatic cutting. Second, a rapidly created and low-voltage electrothermal actuator was developed using an inkjet printed circuit. Finally, a printed robot was fabricated by combining two techniques and two types of paper; a structure design paper and a circuit design paper. Gripper and conveyor robots were fabricated, and their functions were verified. These works demonstrate the possibility of paper mechatronics for rapid and low-cost prototyping as well as of printed robots.

Recently, there has been strong interest in printed robots and paper electronics. Printing is an adequate manufacturing method for the mass production; robots manufactured by printing can be low cost, rapidly creatable and easy to design. Paper is one of smart materials with high water absorbency and strength; it is easily mass-produced at low cost. Many inexpensive and flexible devices were created in paper electronics. Therefore, we propose paper mechatronics that merges printed robots and paper electronics. We used a commercial ink jet printer with water-based ink for self-folding of paper; the paper was folded automatically along the printed line to make the robot body. The paper robot was equipped with a printed electrothermal actuator that consists of epoxy resin covered by conductive ink. The epoxy resin was heated by Joule heat of the conductive ink under a driving voltage of 8 V. The self-folding of experimental paper robot took 15 minutes to construct the body and the robot demonstrated a locomotion at 6.5 mm per step.

Many examples of microfluidic systems have been studied in various fields. Normally, micropumps in microfluidic systems are powered by electricity or heat generated from electric energy and the actuation is controlled by on-off switching of external inputs. Herein we report a novel autonomous flow control inside microfluidic channels powered by self-oscillating gels without external control devices. Self-oscillating gels exhibit a volume oscillation driven by the oscillatory Belousov-Zhabotinsky (BZ) reaction. Our approach greatly simplifies the microfluidic system construction because there is no need for the electric wiring and source. In this paper, we first demonstrate a directional fluid pumping within microfluidic channels and a directional flow rate was 0.02 μL/min utilizing self-oscillating gels. This self-actuated pump could serve as a new framework for microfluidic devices.

In this paper, we report a capsule gel robot that has a novel motion ability. The robot is produced by wrapping a chemical reaction system in a gel membrane and demonstrates a rotary motion by moving the center of gravity. We employed an oil-water system wrapped in a capsule where an oil droplet moves autonomously in water phase. We introduced an alginate gelation technique to make spherical hollow gels, in order to fabricate a membrane of capsule gel robot. The produced capsule gel robot showed a rotary motion in water.

In our previous study, we first succeeded in construction of a novel-types self-oscillting molecular robot. However, the driving environment of the molecular robot was firmly restricted in strong acid conditions. This is because the molecular robots drive induced by the Belousov-Zhabotinsky (BZ) reaction, which is well known for exhibiting temporal and spatiotemporal oscillating phenomena. The overall process of the BZ reaction is the oxidation of an organic substrate, such as malonic acid (MA) or citric acid, by an oxidizing agent (bromate ion) in the presence of a strong acid and a metal catalyst. In this study, in order to drive the novel molecular robot under the physiological condition, we conducted the modification of the molecular structure of the self-oscillating polymer chain. In order to cause the self-oscillation under the biological condition, we synthesized a built-in system where the BZ substrates other than organic acid were incorporated into the molecular robot itself. As a result, the novel molecular robot drives under the biological condition. We believe that the development of the novel molecular robot lead to construction of the novel biomimetic soft robots and actuators, and may inspire novel nonlinear experimental and theoretical considerations.

In this proceeding, we introduce peristaltic gel actuators as a chemical robot. The polymer gels prepared here have a cyclic reaction network like metabolic process in itself. With a cyclic reaction, the polymer gel swells-shrinks autonomously. The periodic self-oscillating motion of the gel is produced by the dissipating chemical energy of the oscillatory Belouzov-Zhabotinsky (BZ) reaction. We have succeeded in convey the object automatically by utilizing the synthetic polymer gel. This experimental fact represents the great possibility of the chemical robot.

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.

Stimuli-responsive polymers and gels have been applied to biomimetic actuators or artificial muscles. Biomimetic robots using such materials can move like a living creature. Especially, electroactive polymers are said to be promising materials as advanced soft actuators. Its mechanical motion is controlled by external stimuli such as a change in solvent composition, pH, temperature and electric field etc. On the other hand, many living organisms generate an autonomous motion without external driving stimuli. In this paper, we report a novel biomimetic gel actuator that can bend and stretch with worm-like motion spontaneously without external driving stimuli. The gel actuator converts the chemical energy of oscillating reaction, i.e., the Belouzov-Zhabotinsky (BZ) reaction into the kinetic energy inside the gel. Although the gel is completely composed of synthetic polymer, it shows autonomous motion as if it is alive. To cause anisotropic contraction with curvature changes, the gel strip with gradient structure was prepared. Furthermore, the gel can walk with repeated bending and stretching motion by itself like a looper by coupling with ratchet mechanism. The "self-walking" gel actuator will create a new framework of biomimetic chemical robot.

The hybrid applications are needed in dental research because the result of their operation could be predicted by both modeling of an oral truct and more than two kind of physical simulations. However, it takes long time to perform the hybrid applications, cost a lot of money and needs some experience to deal with them. This paper proposes a new execution procedure of two applications which can reduce the implementation time by considering parallel efficiency of those applications. It can determine which attitude should be taken, sequential or separate execution of two different applications related with each other. Following the execution procedure, the dental hybrid application was performed. As a result of that, desirable pairs of the number of CPUs allocated to each simulation could be found. This means that the adequate procedure should be considered before execution of the hybrid applications, in order to play a compute power producer for dental clinics and hospitals.