Papers - Narumi, Koya

Weaving and Disguising Infrared Markers toward Invisible Textile Interaction

 2026.04

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Zip-up Print: Rapid and Assemblable 3D printing Using 2D Flattened Zipper-like Structures

 2026.04

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Id tag and detecting system

T IIZUKA, G ITAMI, N KOSAKA, M Maruyama, T Tanaka, A Koyama, J Kato, ...

US Patent App. 18/850,301  2026

GadJets: Air-Jet-Actuated Passive Materials and Mechanisms for Actuated and Shape-Changing Interfaces

S Oka, WY Yang, Y Zou, M Fukuoka, K Narumi, Y Kakehi, K Nakagaki

Proceedings of the Twentieth International Conference on Tangible, Embedded …  2026

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4D Leaf Circuits

Nakaya Y., Fujino K., He L., Narumi K.

Proceedings Scf 2025 10th ACM Symposium on Computational Fabrication  2025.11

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Most of the electric and electronic circuits around us are flat, and ap plying themtodiverse 3Dsurfaces is challenging. This is because (1) printed circuit boards (PCBs) are generally non-stretchable and can not fit doubly curved surfaces, and (2) folding PCBs into non-planar origami geometries requires enormous time and manual effort. To overcome these limitations, we propose 4D Leaf Circuits, a method to automatically fold complex 3D circuits solely through inkjet printing and conductive leaf transfer. We extended the existing 4D printing method using an inkjet printer and added a primer ink layer. This layer worksasanadhesiveforconductiveleaftransferon selected surface areas. Different from previous work on 4D printed circuits, our method does not require an additional screen printing process of conductive ink or any other modification to the printer, which contributes to faster and easier fabrication of 3D objects with circuits. To identify the materials with robust mechanical and electrical properties, we investigated multiple heat-shrinkable films for shape change and conductive leaves for circuits. We also devel oped an algorithm that generates optimal circuit layouts, avoiding mountain folds and minimizing path length. To demonstrate the feasibility of our method, we built three design examples of an in teractive touch-sensing toy, a custom-made mouse, and a portable glow bangle reacting to the user's motion.

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Pneumatic Laser Origami Rapid and Large-Scale Fabrication of Laser-Welded Pouch Motors for Shape-Changing Products

Oka S., Koyama K., Gondo T., Ikeda Y., Kawahara Y., Narumi K.

Proceedings of the 19th International Conference on Tangible, Embedded, and Embodied Interaction, TEI 2025  2025.03

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We propose Pneumatic Laser Origami, a method to rapidly design and fabricate lightweight, self-foldable origami artifacts driven by planar pneumatic actuators called Pouch Motors [18]. Compared to prior methods of building Pouch Motors with customized equipment, we developed a technique to weld two thermoplastic sheets with an off-the-shelf, non-customized laser cutter. This resulted in (1) democratized, (2) faster (> 13 times faster compared to prior methods), and (3) large-scale (85 cm length at maximum) fabrication of shape-changing products. Also, we achieved a method to linearly control the maximum folding angle of Pouch Motors (0◦ < 6 < 95.3◦) by welding extra protrusion patterns, which contributed to driving multiple Pouch Motors with one pneumatic input. To leverage these benefits, we developed the software that takes the target 3D mesh as input and inversely generates a 2D welding pattern for Pouch Motors. Finally, we demonstrated several design examples and applications using our method.

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Pneumatic Laser Origami: Rapid and Large-Scale Fabrication of Laser-Welded Pouch Motors for Shape-Changing Products

S Oka, K Koyama, T Gondo, Y Ikeda, Y Kawahara, K Narumi

Proceedings of the Nineteenth International Conference on Tangible, Embedded …  2025

Designing Balancing Toys Through Mass and Shape Optimization

S Hirata, Y Noma, K Narumi, Y Kawahara

Proceedings of the Special Interest Group on Computer Graphics and …  2025

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We propose an algorithm to interactively design freeform balancing toys that stably balance on a single point of contact. We achieve this by positioning the center of mass outside the model’s surface while deforming the external surface. Our approach relies on a simple energy function that is fast to evaluate and optimize, allowing an interactive design process. The results confirm the feasibility of creating stable balancing toys via standard 3D printing, expanding the possibilities for mechanical design.

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Demonstrating OriStitch: A Machine Embroidery Workflow to Turn Existing Fabrics into Self-Folding 3D Textiles

Z Chang, Y Gao, Y Noma, S Feng, X Yang, K Shinoda, T Ta, K Yatani, ...

Adjunct Proceedings of the 10th ACM Symposium on Computational Fabrication, 1-2  2025

Computational Tailor-Making for Personalized, Shape-changing, and Sustainable Fabrics

K Narumi, Y Hirose, H Lee, M Larsson, L He, M Leake, J Forman, B Farahi, ...

Adjunct Proceedings of the 38th Annual ACM Symposium on User Interface …  2025

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Fabrics are fundamental elements of our daily lives, which are woven, knitted, or embroidered into diverse products like clothing and furniture. Recent advances in materials science and digital fabrication have enabled us to fabricate personalized and responsive fabric products computationally and interactively, which we call “computational tailor-making.” In this workshop, we will build an interdisciplinary network of researchers on computational tailor-making and discuss (1) computational fabric design, (2) novel fabric fabrication tools, (3) shape-changing fabrics, and (4) sustainable fabric production, from the viewpoint of HCI. The workshop session will help attendees build a shared vision, recognize potential challenges, find unexpected solutions and ideas, collaborate beyond disciplines, and explore the possible connection to industries.

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4D Leaf Circuits: Integrating Self-folding Origami and Conductive Leaf Transfer for Freeform Circuits

Y Nakaya, K Fujino, L He, K Narumi

Proceedings of the ACM Symposium on Computational Fabrication, 1-8  2025

ARAP-Based Shape Editing to Manipulate the Center of Mass

S Hirata, Y Noma, K Narumi, Y Kawahara

SIGGRAPH Asia 2024 Posters, 1-2  2024.12

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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.

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Micro-Gesture Recognition of Tongue via Bone Conduction Sound

S Tomaru, K Takaki, H Murakami, D Kim, K Narumi, M Kamezaki, ...

Adjunct Proceedings of the 37th Annual ACM Symposium on User Interface …  2024.10

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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.

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Computational Design and Fabrication of 3D Printed Zippers Connecting 3D Textile Structures

R Masuda, Y Noma, K Narumi

Adjunct Proceedings of the 37th Annual ACM Symposium on User Interface …  2024.10

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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.

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TactPrint: 3D Printing Lattice-based Tactile Displays with Optimized and Local Vibration

R Sakuma, K Narumi, Y Kawahara, T Hiraki

Extended Abstracts of the CHI Conference on Human Factors in Computing …  2024.05

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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.

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Rapid Fabrication of Haptic and Electric Input Interfaces using 4D Printed Origami

S Feng, TD Ta, S Huang, X Li, K Koyama, G Wang, C Yao, Y Kawahara, ...

Extended Abstracts of the CHI Conference on Human Factors in Computing …  2024.05

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Origami is widely used in tangible input interfaces for diverse shapes and haptic feedback. However, the design and fabrication process of origami is labor-intensive, and building circuits on it is often unstable as they can easily be broken during iterative folding processes. We propose a fabrication method that helps users quickly design and fabricate haptic origami interfaces with electric sensing. By extending the previous 4D printing method [16], we developed a design software that can generate both a pattern of self-foldable shape and a pattern of circuitry. In the software, two kirigami hinges and five shape modules are available for users. Kirigami hinges protect the circuits from damage and achieve deformation sensing during the iterative folding process. Five shape modules have different haptic capabilities for different use cases.We summarized the fabrication process and designed three applications to validate our proposed method.

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Folding Angle Control of Inter-Connected Pouch Motors

S Oka, K Koyama, T Gondo, Y Ikeda, Y Kawahara, K Narumi

Extended Abstracts of the CHI Conference on Human Factors in Computing …  2024.05

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Recently, planar pneumatic actuators, known as pouch motors, have gained attention in the fields of soft robotics and Human-Computer Interaction (HCI). However, achieving complex 3D shapes by pouch motors has been hindered by two challenges: (1) the slow operating speed of customized CNC machines, conventionally used for pouch fabrication and (2) the lack of control over the folding angle of individual pouches. To overcome these limitations, (1')we introduce the use of a laser cutter to fabricate pouch motors. This approach enhances the fabrication process, enabling faster production of the pouch motors. Additionally, (2') we propose laser-welding patterns that incorporate small barriers to control the folding angle of each pouch. By manipulating the welding patterns, we achieve nearly linear control over the folding angle of the pouches. In this paper, we present the design and fabrication process of laser-welded planar pneumatic actuators and showcase several design examples.

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Eye-tracking AD: Cutting-Edge Web Advertising on Smartphone Aligned with User’s Gaze

K Tsubouchi, K Taoka, K Ikematsu, S Yamanaka, K Narumi, Y Kawahara

2024 IEEE International Conference on Pervasive Computing and Communications …    469 - 474 2024

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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.

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OriStitch: A Machine Embroidery Workflow to Turn Existing Fabrics into Self-Folding 3D Textiles

Z Chang, Y Noma, S Feng, X Yang, K Shinoda, TD Ta, K Yatani, T Yokota, ...

arXiv preprint arXiv:2412.02891  2024

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OriStitch is a computational fabrication workflow to turn existing flat fabrics into self-folding 3D structures. It uses machine embroidering of functional threads in specific patterns on fabrics, users then apply heat to deform the structure into a target 3D structure. OriStitch is compatible with a range of existing materials (e.g., leather, woven fabric, and denim).We present the design of specific embroidered hinges that fully close under exposure to heat. We discuss the stitch pattern design, thread and fabric selection, and heating conditions. To allow users to create 3D textiles using our hinges, we create a tool to convert 3D meshes to 2D stitch patterns automatically, as well as an end-to-end fabrication and actuation workflow. To validate this workflow, we designed and fabricated a range of application models consisting of up to 338 hinges each (the cap of Figure 1, a handbag, and a vase cover).In technical evaluation, we found that our tool successfully converted 26/28 models found in related papers. We also demonstrate the folding performance across different materials (suede leather, cork, Neoprene, and felt).

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Reusing Cardboard for Packaging Boxes with a Computational Design System

K Koyama, K Narumi, K Takaki, Y Kawase, A Hautasaari, Y Kawahara

Adjunct Proceedings of the 36th Annual ACM Symposium on User Interface …  2023.10

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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.

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