KEIO RESEARCHERS INFORMATION SYSTEM

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• 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.

  • Access to Document (DOI)

• 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

• 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.

  • Access to Document (DOI)

• 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.

  • Access to Document (DOI)

• 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.

  • Access to Document (DOI)

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Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• Laser Pouch Motors: Selective and Wireless Activation of Soft Actuators by Laser-Powered Liquid-to-Gas Phase Change

  Takefumi Hiraki and Kenichi Nakahara and Koya Narumi and Ryuma Niiyama and Noriaki Kida and Naoki Takamura and Hiroshi Okamoto and Yoshihiro Kawahara

  IEEE Robotics and Automation Letters (Institute of Electrical and Electronics Engineers ({IEEE}))  5 ( 3 ) 4180 - 4187 2020.07

  • Access to Document (DOI)

• Liquid Pouch Motors: Printable Planar Actuators Driven by Liquid-to-Gas Phase Change for Shape-Changing Interfaces

  Koya Narumi and Hiroki Sato and Kenichi Nakahara and Young ah Seong and Kunihiko Morinaga and Yasuaki Kakehi and Ryuma Niiyama and Yoshihiro Kawahara

  IEEE Robotics and Automation Letters (Institute of Electrical and Electronics Engineers ({IEEE}))  5 ( 3 ) 3915 - 3922 2020.07

  • Access to Document (DOI)

Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• 機能性と製造性をつなぐ自己折り技術

  2024.04

  -

  2027.03

  学術変革領域研究(B), Principal investigator

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• VISUAL COMPUTING 2

  2025

• VISUAL COMPUTING 1 B

  2025

• VISUAL COMPUTING 1 A

  2025

• SOFTWARE ENGINEERING FOR WEB APPLICATIONS

  2025

• RECITATION IN INFORMATION AND COMPUTER SCIENCE

  2025

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