Published papers

In this demo, we showcase poimo, a series of POrtable and Inflatable MObility devices made of a balloon-like soft material called drop-stitch fabric. Poimo has two merits: (1) inflatability of a soft and lightweight body allowing users to deflate and carry it on a small scale and (2) inclusiveness enabling made-to-order design and fabrication of mobility devices for each user. As an alternative way to conventional rigid controllers, we also introduce a soft and deformable input interface to navigate a sofa-type poimo. Finally, we report two types of field studies: public users riding on two types of poimos on a flat paved road, and the authors riding on a sofa-type poimo in a traditional European environment with inclined stone-paved streets.

Advertisements displayed on a narrow smartphone screen often disturb the user's operation of the application. Regarding information display methods, the challenge is how to reduce discomfort while still attracting the user's interest. In this study, we propose a new method of presenting advertisements, called Eye-tracking AD, which constantly observes the user's gaze and changes the movement and information of the advertisement accordingly. Eye-tracking AD was implemented as an actual application and evaluated by 745 users. As a result, it was found that eye-tracking AD reduced the degree of discomfort while increasing the recall of advertisements. The results are promising for practical use in the future.

We propose Inkjet 4D Print, a self-folding fabrication method of 3D origami tessellations by printing 2D patterns on both sides of a heat-shrinkable base sheet, using a commercialized inkjet ultraviolet (UV) printer. Compared to the previous folding-based 4D printing approach using fused deposition modeling (FDM) 3D printers [An et al. 2018], our method has merits in (1) more than 1200 times higher resolution in terms of the number of self-foldable facets, (2) 2.8 times faster printing speed, and (3) optional full-color decoration. This paper describes the material selection, the folding mechanism, the heating condition, and the printing patterns to self-fold both known and freeform tessellations. We also evaluated the self-folding resolution, the printing and transformation speed, and the shape accuracy of our method. Finally, we demonstrated applications enabled by our self-foldable tessellated objects.

Recognizing the significant potential impact that HCI has on food practices and experiences, researchers and practitioners are undertaking a growing number of explorations of novel computing technology and food combinations. These explorations have so far primarily emphasized technology-driven systems and taken a human-centric perspective. We propose a Special Interest Group (SIG) in "foodHCI futures"that creates a space for researchers to discuss the boundaries of food incorporating HCI, and with the simultaneous aims of reconciling food with technology and extending our visions for human-food interactions towards anthropocentrism. Specifically, the SIG will be a beginning of developing a structured conceptual map of the possibilities for future technology interventions in food systems. In developing this map, we hope to encourage democratized debate, provoke new and divergent thoughts on the opportunities for foodHCI, and ultimately gain unique insights that contribute to preferable food futures.

We propose a hands-free and less perceptible gesture sensing method of the tongue by capturing the bone conduction sound generated when the tongue rubs the teeth. The sound is captured by the bone conduction microphones attached behind the ears. In this work, we show that tongue slide, snap, and teeth click gestures can be classified using the decision tree algorithm, which focuses on the characteristics in the sound spectrogram. We conducted a preliminary experiment to verify that input methods for mouth microgesture devices using bone conduction can be expanded from only teeth to teeth and tongue gestures without any additional obtrusive sensors. The evaluation revealed that our method achieved a classification accuracy of 82.7% with user-specific parameter adjustment.

We propose a computational design system for packaging boxes, which enables reconstruction of cardboard into packaging structures that precisely fit the size of the objects to be shipped. Given a 3D model of the object and the structure of the cardboard to be reused, our system suggests the optimal net of a new box, which only requires minimum cuts and folds for fabrication by leveraging the edges of the input cardboard. To achieve this, we implemented a GUI visualizing the input models and the optimal net computed by our optimization algorithm. As a demonstration, we showed three design examples, with evaluation results of our method for reducing the length of cuts and folds.

Tactile sensation is widely used in human-object interactions. However, designing local vibrations within a device's enclosure, while considering the propagation characteristics of the vibrations, is still challenging, which often results in the entire device vibrating uniformly. In this paper, we introduce TactPrint, a method that involves embedding a lattice structure around the area where we want to induce local vibrations and then optimizing this 3D structure to create a tactile display with the desired local vibration characteristics. With the TactPrint system, users can obtain structures with desired local vibration characteristics simply by inputting a 3D model, which can be fabricated with a 3D printer and combined with an actuator to create a tactile display easily. In this demonstration, we present several prototypes of tactile displays created using our proposed system and application scenarios using them.

Widespread research is being conducted on computational materials. The challenge for the realization of computational materials is how to weave computers into everyday objects consisting of various shapes and form factors. One idea to achieve this vision is to build physical computational particles that can cooperatively communicate among others and, thereby, change the whole shape like clay. Wireless communication and power transfer are keys to making such computing particles happen. Thus, we introduce an approach to embody these particles using multiple tiny IC chips, which wirelessly cooperate with each other. This article shows the current state-of-the-art wireless communication and power transfer technologies integrated into IC chips to achieve fine-grained shape deformation of computers. Moreover, this article also presents recent trends and future directions in shape-changing human-computer interfaces research.

We propose an algorithm to align the center of mass of an input shape to a prescribed point. Unlike previous approaches that rely on hollowing the inner structure, our method deforms the outer shape by incorporating As-Rigid-As-Possible (ARAP) energy. Our method provides two editing modes: one prioritizing speed and the other focusing on accuracy. Combining these two modes, users can interactively explore the design space of shapes while achieving the desired center of mass positioning.

Zippers have long been used for connecting and disconnecting two textiles repeatedly and easily. However, many industrial zippers cannot retain their shape after assembly, limiting the potential use of connecting soft textiles to form 3D shapes with large and various curvatures. Thus, we present a method to design and fabricate interlocking 3D printable zippers that can encode post-assembly shapes. The user first gives a target 3D shape divided into developable patches (i.e., curved surfaces unrollable like paper). Then, our design software built on Rhino/Grasshopper computes an interlocking zipper on the boundary curve of the patches. The user 3D prints the zipper in a flat state and welds it to the edge of the textiles by thermal bonding, which can zip into a target 3D shape. In this demo, we report our method and exhibit design examples of 3D printed zippers.

Flower jellies, a delicate dessert in which a fower-shaped jelly foats inside another clear jelly, fascinate people with both their beauty and elaborate construction. In eforts to simplify the challenging fabrication and enrich the design space of this dessert, we present Flower Jelly Printer: a printing device and design software for digitally fabricating fower jellies. Our design software lets users play with parameters and preview the resulting forms until achieving their desired shapes. We also developed slit injection printing that directly injects colored jelly into a base jelly, and shared several design examples to show the breadth of design possibilities. Finally, the user study with novice and experienced users demonstrates that our system benefts creators of all experience levels by iterative design and precise fabrication. We hope to enable more people to design and create their own fower jellies while expanding access and the design space for digitally fabricated foods.

Flower jellies, a delicate dessert in which a fower-shaped jelly foats inside another clear jelly, fascinate people with both their beauty and elaborate construction. In eforts to simplify the challenging fabrication and enrich the design space of this dessert, we present Flower Jelly Printer: a printing device and design software for digitally fabricating fower jellies. Our design software lets users play with parameters and preview the resulting forms until achieving their desired shapes. We also developed slit injection printing that directly injects colored jelly into a base jelly, and shared several design examples to show the breadth of design possibilities. Finally, the user study with novice and experienced users demonstrates that our system benefts creators of all experience levels by iterative design and precise fabrication. We hope to enable more people to design and create their own fower jellies while expanding access and the design space for digitally fabricated foods.