Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1115/1.4055823

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41598-022-08314-w

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41598-021-98242-y

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English  

Language：English   Publishing type：Research paper (other academic)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1073/pnas.2005769117

Language：English   Publishing type：Research paper (other academic)  

DOI： 10.1145/3313831.3376655

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1587/comex.2019GCL0031

Language：Others   Publishing type：Research paper (other academic)  

DOI： 10.1145/3290607.3312872

Language：English   Publishing type：Research paper (other academic)  

DOI： 10.1145/3290605.3300858

Language：Others   Publishing type：Research paper (other academic)  

DOI： 10.1145/3290607.3312757

Language：Japanese  

折り紙は、大きな構造をコンパクトに収納できる性質から宇宙展開構造物に、軽さと強さを兼ね備えた折り紙構造建築になど、様々な分野に応用されてきた。近年では、折り紙の小面を電極として用いることで、キャパシタやスピーカーなどの電子回路的な応用が増えた。平坦折りできる展開図は2色に塗り分けられることが古くから知られている一方で、ジャンプワイヤなどの手間が不要になる「連結した2色への塗り分け」は考慮されてこなかった。本論文では、「どのような展開図ならば連結した2色への塗り分けパターンが存在するか？」の判別法と、「塗り分け不可能なパターンを塗り分けるためにどのような修正が可能か？」を紹介する。

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.asr.2018.09.020

Language：English   Publishing type：Research paper (other academic)  

Crawling Cylindrical Origami Robot Driven by Single Actuator

Language：English  

第28回アストロダイナミクスシンポジウム (2018年7月30-31日. 宇宙航空研究開発機構宇宙科学研究所), 相模原市, 神奈川県資料番号: SA6000135021レポート番号: A-21

Language：Japanese  

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Language：Japanese  

ロボットを用いた電線のメンテナンスロボットなど、直線状の物体上に沿って移動するロボットが存在する。そのようなロボットを我々は折り紙で実現する手法を提案する。直線上の物体を包み込むように円筒折を配置し、その展開と収縮で移動する。円筒折は折れると内径が小さくなる構造である。内径が小さくなることで直線状の物体を把持する。異なる剛性の円筒折を組み合わせることで、最も剛性の小さい円筒折から順に折れ、最も剛性の小さい円筒折から展開する。これにより、ロボットを伸縮させるだけで、剛性が小さい円筒折の方向に進行する。形状記憶合金や、内部への気体の封入で駆動することで、ロボットの軽量化が可能である。

Language：Japanese  

本研究では,折紙のように1枚のシートからの折り曲げのみで構成される3次元の体躯に,アクチュエータとしての形状記憶合金を付けることで実現する,伸縮運動により這行運動をするシンプルなイモムシ型ロボットを実装する。このロボットは機械的機構が簡潔で,極めて安価に作製可能であり,伸縮の波の伝播方向を変えるだけでロボットの進行方向を制御することも可能である。本稿では,この折り紙ロボットの体節伸縮の波伝播運動のメカニズムに着目し,折り目の構造及び形状記憶合金が発生させる力の大きさとタイミングを分析し,効率的な這行運動を生成可能なパターンを見つけ出す。

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.matdes.2017.06.014

Language：English   Publishing type：Research paper (other academic)  

DOI： 10.1115/DETC2017-67697

Language：English  

DOI： 10.1073/pnas.1709196114

Language：English   Publishing type：Research paper (scientific journal)  

Design and fabrication of aluminum honeycomb structures based on origami technology

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1073/pnas.1620612114

Language：Others   Publishing type：Research paper (other academic)  

Experimental Research on Roll-up Storage Method for a Large Solar Sail

Language：Others   Publishing type：Research paper (other academic)  

Design of single/double curved honeycomb cores based on origami techniques

Language：English   Publishing type：Research paper (other academic)  

DOI： 10.1115/DETC2016-60419

Language：Japanese  

This study presents a new method for designing self-deploying origami using the geometrically misaligned creases. In this method, some facets are replaced by "holes" such that the systems become a 1-DOF mechanism. These perforated origami models can be folded and unfolded similar to rigid-foldable (without misalignment) models because of their DOF despite the existence of the misalignment. Focusing on the removed facets, the holes will deform according to the motion of the frame of the remaining parts. In the proposed method, these holes are filled with elastic parts and store elastic energy for self-deployment. First, a new extended rigid-folding simulation technique is proposed to estimate the deformation of the holes. Next by using the above technique, the proposed method is applied on arbitrary-size quadrilateral mesh origami. Finally, by using the finite-element method, the authors conduct numerical simulations and confirm the deployment capabilities of the models.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1177/1475921715624503

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1098/rspa.2015.0235

Language：Others   Publishing type：Research paper (other academic)  

Beetle Inspired Deployable Structures

Language：Japanese  

Foldable hindwings in beetles are one of the ultimate deployable structures. They have sufficient strength and stiffness to tolerate 20-1000 beats per second in the flight position, although they can be folded and unfolded nearly instantly depending on the situation. This study focuses on a group of beetles that have unfolding-stable-type wings and aims to reveal their wing-folding/unfolding mechanisms. These beetles use their wing elasticity for deployment and can therefore quickly take off. First, on the basis of the reports of entomologists, the authors describe the factors related to the actuation of insect wing folding and unfolding. Then, the detailed motions involved in take-off and wing storing in ladybird beetles and rove beetles are observed by a high-speed camera. The analysis of these movies reveals the detailed processes of wing-unfolding and folding in these two species. Intrinsic elasticity plays a major role in wing development in both species. In the case of wing storing, a ladybird beetle folds its hindwings into a symmetric pattern using a simple up-down movement of the abdomen, whereas rove beetles also use their abdomens for wing-folding, but their movements are more complex, and the crease patterns are asymmetric. Finally, the characteristics of each wing-folding mechanism are summarized and the potential for engineering applications are discussed. Wing-folding/unfolding mechanisms in these insects have various unique capabilities which will provide new possibilities for designing deployable structures.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1177/1475921714560074

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1115/1.4029228

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1073/pnas.1409468111

Language：Japanese  

Artful wing folding of insects has attracted the interest of aerospace engineering scientists as well as entomologists. Foldable hindwings are the ultimate deployable structures. They have sufficient strength and stiffness to tolerate 20-1000 beats per second in the flight position, although they can be folded and unfolded instantly depending on the situation. Entomologists point out that insect wings can be classified into the following two groups based on structural characteristics: folding-stable type and unfolding-stable type. In each group, the movement toward a stable point is easy to achieve because it can be triggered by a small force and progresses automatically by elastic force. Naturally, problems are observed mainly in reverse-directed movements that require a larger force to cross the peak of elastic energy. Some insects address these problems by unique and somewhat heavy-handed methods. Despite large potential for engineering application, few studies have been undertaken to reveal these characteristic movements. This study used a high-speed camera to observe the folding and unfolding movements of some beetles. The revealed folding/unfolding mechanisms can achieve not only highly compact wing storage but also immediate deployment/folding. They offer significant potential for space deployable structures.

Language：Japanese  

In this research, phase-shifted FBG (PS-FBG) sensor was employed to practical AE detection for carbon fiber reinforced plastic (CFRP) composite laminate. Firstly, we evaluated the characteristics of AE signals detected by this kind of sensor. Secondly, through the experiment and simulation concerning AE source orientation, quantitative information about the standard for discriminating the AE signals due to transverse cracks and delaminations was obtained. Finally, according to the standard, we identified the occurrence of those two damage types successfully from the actually detected AE signals under three point bending and tensile tests.

Language：Japanese  

This study presents a new method for designing self-deploying origami using the geometrically misaligned creases. In this method, some facets are replaced by "holes" such that the systems become a 1-DOF mechanism. These perforated origami models can be folded and unfolded similar to rigid-foldable (without misalignment) models because of their DOF despite the existence of the misalignment. Focusing on the removed facets, the holes will deform according to the motion of the frame of the remaining parts. In the proposed method, these holes are filled with elastic parts and store elastic energy for self-deployment. First, a new extended rigid-folding simulation technique is proposed to estimate the deformation of the holes. Next by using the above technique, the proposed method is applied on arbitrary-size quadrilateral mesh origami. Finally, by using the finite-element method, the authors conduct numerical simulations and confirm the deployment capabilities of the models.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1115/1.4026824

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/s140101094

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

This paper presents a new impact identification method using the high-speed strain measurement system. This system consists of fiber Bragg grating (FBG) sensors and an arrayed waveguide gratings (AWG) filter, and can detect large strain waves such as the impact strain waves. Firstly, we propose new algorism for calculation of coordinates of the impact-loaded point. Although conventional detection methods are carried out under the condition that the propagation speed of the elastic wave is given, this proposed method enables us to calculate the position of a wave source without its speed. This algorism also has the great versatility of sensors positions. Next, the high-speed strain measurement system used in this study is mentioned. Using multiplexed FBG sensors, this system can detect the strain wave on four different points at the same time. Finally, the impact identification tests are carried out on the carbon Fiber reinforced plastic (CFRP) laminate. The aforementioned algorism are used to calculate the impact loaded position from the difference for the arrival times of the four sensor points. The results indicate the correct position with relatively small errors.

Language：Japanese  

As represented by Miura-ori, origami has inspired various types of deployable structures. Usually, these Origami structures are designed under the assumption of "rigid folding", which means each plane is undeformable and connected with ideal joints. The authors proposed a new strategy for designing deployable structures by using partially elastic origami models. These new origami structures take into account the elastic deformation. It enables us to estimate the elastic energy through folding and unfolding process and to design self-deploying origami structures. This paper presents the manufacturing methods for the deployable structures based on partially elastic origami. The challenge is summarized in two main problems: treating of plate thickness and designing for hinge parts. Firstly, the authors propose the method using commercially available hinges and make the sample of aluminum alloy plate. Secondly, by using 3D printer, some plastic samples are made and the representative one is shown. Finally, the deformations of elastic parts in these trial models are compared with a theoretical model.

Language：Japanese  

As represented by Miura-ori, origami has inspired various types of deployable structures. Usually, these Origami structures are designed under the assumption of "rigid folding", which means each plane is undeformable and connected with ideal joints. The authors proposed a new strategy for designing deployable structures by using partially elastic origami models. These new origami structures take into account the elastic deformation. It enables us to estimate the elastic energy through folding and unfolding process and to design self-deploying origami structures. This paper presents the manufacturing methods for the deployable structures based on partially elastic origami. The challenge is summarized in two main problems: treating for plate thickness and designing for hinge parts. Firstly, the authors propose the method using commercially available hinges and make the sample from of aluminum alloy plate. Secondly, by using 3D printer, some plastic samples are made and the representative one is shown. Finally, the deformations of elastic parts in these trial models are compared with a theoretical model.

Language：Japanese  

As represented by Miura-ori, origami has inspired various types of deployable structures. Usually, these Origami structures are designed under the assumption of "rigid folding", which means each plane is undeformable and connected with ideal joints. In this study, a new strategy for designing deployable structures are proposed by using partially elastic origami models. These new origami structures take into account the elastic deformation. It enables us to estimate the elastic energy through folding and unfolding process and to design self-deploying origami structures.

Language：Japanese  

As represented by Miura-ori, origami has inspired various types of deployable structures. Usually, these Origami structures are designed under the assumption of "rigid folding", which means each plane is undeformable and connected with ideal joints. In this study, a new strategy for designing deployable structures are proposed by using partially elastic origami models. These new origami structures take into account the elastic deformation. It enables us to estimate the elastic energy through folding and unfolding process and to design self-deploying origami structures.

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1177/1045389X11416030

Language：Japanese  

Dia-Core is a newly devised core panel formed by gluing/welding of two same shaped panel pieces which have periodically indents. The basic model of Dia-core is based on Octet-Truss developed by Fuller, and it consists of tetrahedra and octahedra. It has good cost performance due to easy press forming. Therefore, it is expected to become new core materials which can compete with honeycomb panels from the total points of view. In this paper, by using experiments and numerical simulations, the bending rigidity, a representative propertie of Dia-Core is clarified. The results suggest that the bending rigidity of Dia-core is proportional to the initial thickness of panel pieces and the square of the panel height. These trends can be explained by the application of the theory of sandwich structures. And by using these results, the specific rigidity of Dia-core is calculated and compared with that of two typical honeycomb panels.

Language：Japanese  

In this paper, we present the vibration analyses of Trass core panel. Trass core panel is newly devised lightweight core panel and has general versatility. We conducted the vibration analyses and excitation experiment to obtain the vibration characteristics such as Eigen frequency and Eigen mode, then we compared the Eigen frequency of a Trass core panel to that of the flat panel which weight is equal to the Trass core panel.

Language：Japanese  

Dia-Core is a newly devised core panel formed by gluing/welding two same shaped panel pieces which have periodical indents. It has good cost performance due to easy press forming. Therefore, it is expected to become new core material which can be compete with honeycombs from the total points of view. The basic model of Dia-core is based on Octet-Truss developed by Fuller, and it consists of tetrahedra and octahedra. By varying the geometrical patterns that appear on the panel surfaces, various shaped modified models are devised systematically. In this paper, it is clarified that these pattern variations can be ruled by two geometric parameters, truncation [k ] and separation [s]. Next, by numerical simulation using FEM, effects of these two parameters on the representative properties of Dia-Core, bending and in-plane shear rigidity, are clarified.

DOI： 10.1299/kikaia.74.1580

Language：Japanese  

Language：Japanese  

平面/空間充填形の概念に基づいて開発された新しいコアパネル(ダイアコア)は,プレス加工されたパネル片を2枚対称に接合することによりハニカムコアよりもはるかに安価に製作できる.それゆえ実用化されれば様々な製品への応用が期待され,オクテットトラス型の基本モデル以外にも様々なデザインを持つ多数の発展型モデルが開発されている.本論文はその多様な幾何学的パターンを2つのパラメータを用いて数理的に表す方法を明らかにすると共に,有限要素法を用いてこれらのパラメータがパネルの曲げ剛性,面内せん断剛性に与える影響を明らかにする.

Language：Japanese  

This paper deals with a new core structure panel, called Truss Core Panel. We consider this Panel is useful for environment concern, because this panel has high-specific stiffness, such as Honey Comb Panel. And more, this Panel is formed by Press Forming. So, we think it leads more general versatility unlike Honey Comb Panel that has multi forming process. And now Truss Core Panel changes its core shape based on Truncation parameter, k and Separation parameter, s. So we think this feature changes mechanical characteristic of Truss Core Panel. In this paper, we examined formability of Truss Core Panel according to Truncation parameter, k and Separation parameter, s. through the dynamic FEM simulation. As a result, Relation between Thickness Reduction and Truncation parameter, k became nonlinear in certain Separation parameter, s. And we examined strength characteristic of Truss Core Panel after Press Forming. So this panel has the effect of work hardening. As a result, Relation between Mean Load cf Panel and Truncation parameter, k became almost linear despite Separation parameter, s. In conclusion we showed Formability and Strength Characteristic affer Press Forming do not always relate in the same condition.

Language：Japanese  

By processing triangle or square pyramid shaped indents on a flat sheet, panels with periodical indents in regular plane tiling patterns are manufactured. Highly rigid core panels are newly developed by setting this panel (as top panel) on a reversed one (as bottom panel), and gluing/ welding them at the apexes of pyramids to the vertexes of the tiling patterns in the bottom panel. The basic model named Dia-Core is a panel created in the form of Octet-Truss developed by Fuller which corresponds to the space filling model consisting of a combination of two tetrahedra and one octahedron. By varying the geometric patterns that appear on the panel surfaces, all possible patterns based on geometrical considerations are devised, systematically creating various modified models with larger welding portions.

DOI： 10.1299/kikaia.73.1302

Language：Japanese  

By allowing elastic deformation in truss members, it is investigated whether or not shape-changable/variable geometry truss structure can be designed based on the origami models of foldable cylindrical and conical shells. Stability (or instability) and statically determinate(or indeterminate) conditions in truss structures, whose nodes consists of 6 members are examined under conditions with both rigid members and elastic members. It is exemplified that foldable/deployable truss structures can be designed when members are elastic.

Language：Japanese  

Today, we need more lightweight and more high stiffness panels, because of environment concern. Especially this demand is strong for automobile vehicles. Here we examine the application possibility to the door structure for the side collision of vehicles etc., paying attention to the Truss Core Panel, invented by Nojima based on "filling theory". Then, we evaluate its bending characteristic through the dynamic non-linear FEM simulation. And we select design variables of Truss Core Panel to examine the sufficiency of its bending characteristic. In this research, three conclusions are obtained as follows; 1) The evaluation value becomes high by making the "flat rate gamma" small 2) The evaluation value also becomes high as "triangular pyramid cutting" length becomes large. 3) If panel board thickness becomes 60&#37; or less, the evaluation value greatly down. Thus, it is important to calculate the optimal value considering both of "formulability and bending characteristic" for its utilization .

Language：Japanese  

By processing triangle or square pyramid shaped indents on a flat sheet following regular plane tiling patterns, panels with periodical indents are manufactured. By setting a panel piece (as top panel) on reversed one (as bottom one), and gluing them at the apexes of pyramids to nodal points of the tiling patterns of bottom panel, highly rigid core panels are newly developed. By analyzing mechanical property of these core panels with experiments and numerical simulations, it is clarified that surface patterns affect panel rigidity, and they are able to compete with honeycomb at the point of specific rigidity

Language：Japanese  

Language：English  

I-1 DEVELOPMENT OF LIGHT WEIGHT RIGID CORE PANELS(Session: Casting/Molding)
By processing triangle or square pyramid shaped indents on a flat sheet following regular plane tiling patterns, panels with periodical indents are manufactured. By setting this panel (as top panel) on reversed one (as bottom panel), and gluing them at the apexes of pyramids to nodal points of the tiling patterns of bottom panel, highly rigid core panels are newly developed. The basic model named "dia-core" corresponds to the space filling models by two tetrahedra and one octahedron. Besides, varying the geometric patterns which appear on their surfaces, various modified models are devised. This pattern variation is known as Archimedean plane tiling in geometry.

Language：Japanese  

By processing triangle or square pyramid shaped indents on a flat sheet following regular plane tiling patterns, panels with periodical indents are manufactured. By setting this panel (as top panel) on reversed one (as bottom panel), and gluing them at the apexes of pyramids to nodal points of the tiling patterns of bottom panel, highly rigid core panels are newly developed. The basic model named "dia-core" corresponds to the space filling models by two tetrahedra and one octahedron. Besides, varying the geometric patterns which appear on their surfaces, various modified models are devised. This pattern variation is known as Archimedean plane tiling in geometry.

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1299/jsmea.49.38

Language：Japanese  

By folding a thin flat sheet with periodically set slits or punched out portions into the third dimension, ultra-lightweight strong and functional core models are newly devised. The basic idea of this modeling arises from the application of origami technique to engineering. Based on the space filling models, fundamental flat cores and skew type sponge cores have been newly developed. By applying these models, tube shaped core and curved cores are newly devised.

Language：English  

Country：Other  

New deployable structures based on an elastic origami model

Language：English  

Country：Other  

Manufacture of arbitrary cross-section composite honeycomb cores based on origami techniques

Language：English  

Country：Other  

Designing of self-deploying origami models using geometrically misaligned crease patterns

Language：Japanese  

Country：Other  

Language：Japanese  

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Language：English  

Country：Other  

Elastic wing deployments in beetles and their folding mechanisms

Language：Japanese  

Country：Other  

Language：English  

Country：Other  

Design of a 3D wing honeycomb core based on origami techniques

Language：Japanese  

Country：Other  

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Design of a beetle inspired deployable wing

Language：Japanese  

Country：Other  

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Country：Other  

Demo: Origami robots with flexible printed circuit sheets

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Country：Other  

Patterns in Insect Wings

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Country：Other  

Folding Patterns in Insect Wings

Language：Others  

Country：Other  

Language：Japanese  

Country：Other  

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Country：Other  

Language：Others  

Country：Other  

3D structural form creation of earwig fan using the algorithmic design tool

Language：Others  

Country：Other  

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Country：Other  

Language：Japanese  

Country：Other  

Language：English  

Country：Japan  

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Country：Other  

Language：Others  

Country：Other  

Audience： Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience： General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience： General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience： General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Seminar, workshop

Audience： General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience： Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Audience： General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

日本経済新聞，2023年1月22日朝刊に掲載された連載「生き物に学ぶ」においてハサミムシの翅の生物模倣工学についての研究が取り上げられた．

2022年9月23日朝刊の科学・医療面「昆虫の構造　技術に生かす」において，ハサミムシの翅の折り畳みに関する研究が紹介された．

NHK Eテレ「ミミクリーズ」，はねをたたむ(初回放送日: 2021/11/8)の監修

NHK Eテレ「ミミクリーズ」，はねをひらく(初回放送日: 2021/2/15)の監修

2020年11月号，付録「ハサミムシペーパークラフト」のデザイン，監修