International Digital Modeling Contest 2024
IDMC 2024 Catalogue
Editors of IDMC 2024 Catalogue
Aya SAITO
Misako NISHII
Office be one Inc.
Logo and Cover Design
Aya SAITO
Organized by
Japan Society for Graphic Science (JSGS)The University of Tokyo, Komaba I Campus
3-8-1 Komaba, Meguro-ku, Tokyo 153-8902
Contact: idmc2024@graphicscience.jp
This contest is supported by JSPS KAKENHI Grant Number JP23HP0701.
Published in August 2024
Copyright© 2024 Japan Society for Graphic Science. All Rights Reserved.

Contents

International Digital Modeling Contest 2024……………………………………………………

1

Finalist “Prosthetic Armor: Restoring the Human Body”………………………………………

4

Finalist “3D Printed Origami Cellular Material Switching DOF and Poisson's Ratio”………

6

Finalist “Curved surface print without support material”………………………………………

8

Finalist “A model of the Taj Mahal for tactile and visual recognition”………………………

10

Finalist “I Interactive 3D zoetrope, with manual strobe lights”………………………………

12

Finalist “3D printed Splinter prosthesis socket for forearm amputees”………………………

14

Finalist “Prosthetic Forearm Socket Design
New Possibilities Fusion of 3DCAD and Leather”…………………………………

16

Finalist “A study for tessellation with motif of Escher”………………………………………

18

3

International Digital Modeling Contest 2024

International Digital Modeling Contest 2024
The International Digital Modeling Contest 2024 (IDMC2024) aims to promote the use of fundamental technologies that inspire thecreation of three-dimensional mechanisms and objects in a new and innovative environment centered on additive manufacturing (3Dprinters).
In this contest, we invited entries of works in which 3D data created by digital modeling from the original plan was output by a 3D
printer, and the entire process was verified.
The Japan Society for Graphic Arts has held the “Digital Modeling Contest” for the past 17 years. Based on this experience, thisyear's contest was expanded to cover a wider range of fields, and entries were also invited from overseas.
Purpose of the contest
The Digital Modeling (Digital Content) Contest positions creation as an academic activity and will be held while maintaining thecontest format. One of the goals of the contest is to explain in an easy-to-understand manner the process from the purpose of creating
the work to the model production, with an emphasis on necessity and preservation of the process. To make effective use of 3Dmodeling machines, it is important to have content that can be used for 3D modeling, such as educational works and resource works.
Judging schedule
August 8, 2024 Short Presentation
August 9, 2024 Awards ceremony
Exhibition (Open to the public period)
August 6, 2024 - August 9, 2024
Venue
Kitakyushu International Conference Center
3-9-30 Asano, Kokurakita-ku, Kitakyushu-shi, Fukuoka 802-0001

1

Jury Committee, Executive committee

Contact

Jury committee

idmc2024@graphicscience.jp

Jury committee Chair
Kensuke YASUFUKU

Organized by

Japan

Japan Society for Graphic Science
Jury committee Vice-Chair
Yoshizumi FUKUE

Japan

Jury committee members
Alison MARTIN

Italy

Masakatsu MATSUYAMA
Tsutomu ARAKI

Shigekazu ISHIHARA
Keiko ISHIHARAAya SAITO

Japan

Japan
Japan

Japan

Japan

Akihiro SHIBATA

Japan

Emiko TSUTSUMIJapan

Koichi MATSUDA

Japan

Toshio MURAMATSU

Japan

Yayoi YOKOYAMAJapan

Akihiro MATSUURAJapan

Executive committee Chairman
Hirotaka SUZUKI

Japan

Vice-chairman
Yuji KATAGIRIJapan

Committee members
Shota ISHIIJapan

Tomoko OHTANI
Daiji OKADA
Ai SAKAKI

Japan

Japan
Japan

Maiko K. TSUJIIJapan

Kidai NAKANOJapan

Misako NISHIIJapan

Tatsushi TANAKA
Ryuta MOTEGI

Japan
Japan

Naoyuki MIYAKOSHI

Japan

Technological cooperation
Saitama Industrial Technology Center

2

Finalist

Finalist3

Finalist

Prosthetic Armor: Restoring the Human Body
Scott Jurgens
International Kansei Design
sjurgens323@gmail.com

Figure 1: Prosthetic armor mock-up, 3D modeled in 2023

Keywords: prosthetics, kansei design, 3D printing

process of recovery and learning to use their new limb,
amputees experience self-esteem issues that affect their
willingness to practice with the new limb in public [1].
Additionally, studies have revealed that most prosthetic users
were dissatisfied with the aesthetics of their foam cover [2].
This feeling among prosthetic users has led to the design of a
new type of cover that looks less like a medical device andmore like a fashion accessory and a piece of emotional design,
following the principles of Kansei engineering. This issomething I will call prosthetic “armor”, using this word tocall on the human-based and aesthetic designs armor alongwith its protective qualities. A designer can assist theprosthetic technician and amputee, providing concept
drawings, using 3D printing and post-processing to provide abeautiful, personalized and custom fit prosthetic armor.

Abstract
As prosthetic devices improve in function, the users’ quality oflife is improved, allowing independence and freedom ineveryday activities. However, the amputee still experiences
confidence and body image issues based on social stigmas.
Current standard of care in the aesthetic aspect of prosthetic
devices do not adequately address this issue. This is the reason
behind this case of designing a personalized prosthetic coverusing low-cost, rapid production pipeline with 3D printing foran adult subject who uses a prosthesis with a trans-femoral
amputation.

1 Concept
Prosthetic lower limbs for trans-femoral amputees arecomprised of a socket, adapters, a knee, a metal pylon, a foot,and an exterior cosmetic and protective piece called aprosthetic cover. The prosthetic covers that are widely
available are manufactured to look realistic, using a simple
skin tone color on a foam material in leg shape. During their

2 Production process
The production process of a prosthetic armor begins withtaking pictures of the subject in the anterior, posterior and4

Finalist

lateral planes and measurements the subject’s sound limb
length from knee to ankle and circumferences at the largest
and smallest parts of the calf. I administered a questionnaire to
the subject to decide on details such as shape, color, texture,and surface design. Designing and 3D modeling took placefrom September to November 2023 with the subject’s datataken at Hiroshima International University and production of
the 3D printed prosthetic armor pieces began in March 2024
and printed in April 2024. A functional prosthetic armor withhinges and a clamp to connect to the prosthetic pylon iscurrently being developed as of May 2024.

simply for its convenient availability. *I don’t recommend thisprinter for adult-sized prosthetic armor due to its print volumeof 250 x 210 x 210 mm. The anterior panel was printed in twopieces, so I used industrial strength glue to join them together
and used silicone to fill in any gaps.

2.4 Post-processing
The panels were then sanded down with #60, #110 and #220
grit sandpaper in succession to smooth the surface and prepare
it for priming and painting. Primer was sprayed onto thepanels, followed by white gloss primer and paint spray,followed by another sanding with the same series of grit
sandpaper as before to further refine the surface. Finally, awhite gloss primer and paint was sprayed onto the panels anda wax metallic silver finish was rubbed onto the pieces with asponge stick to achieve a reflective metal quality (Fig. 3).

2.1 Design
A series of concept designs were drawn by me using thepatient’s questionnaire. In this case we decided on a medieval“fluted” European-style greave, or leg armor aesthetic whichfeatures a basic symmetrical shape, sharp anterior edge andmetallic texture and color. The basic structure of the cover ismade up of anterior and posterior panels that can attach toeach other with a hinge and a latch with a detachable clamp
built into the posterior panel that fastens around the pylon.

2.2 3D Model
In Blender, I imported reference pictures of the subject andoutlined his sound limb using vertex placements. Once theinitial vertices are positioned, I connected them to makepolygonal shapes and adjusted the shapes to match thesubject’s leg in 3D. The anterior and posterior panels of thearmor are derived from this base shape and sculpted into thefinal design (Fig. 2). A mock-up image is made with texture
maps with the 3D render of the prosthetic armor on thesubject’s prosthetic leg to share with the subject for approval
to move forward with production (Fig. 1).

Figure 3: Prosthetic armor, size 117 x 143 x 374 mm, PLA,
3D printed in 2024

3 Software & System
Blender ver. 3.4, PrusaSlicer ver 2.7.2, Prusa i3 MK3*,
Windows 11.

References
Figure 2: Final 3D model design[1] Holzer L. A., Sevelda F., Fraberger G., Bluder O.,
Kickinger W., Holzer G., Body image and self-esteem inlower-limb amputees, PLoS ONE 2014[2] Sansoni, S., Speer, L., Wodehouse, A., Buis, A., Aestheticof Prosthetic Devices: From Medical Equipment to a Work of
Design, Emotional Engineering, Vol. 4, pp.73-92, Springer
International Publishing Switzerland 2016

2.3 3D Print
The anterior and posterior panels of the prosthetic armor werethen exported separately as .STL files and imported toPrusaSlicer and positioned on the print bed with supports. The
G-Code data was exported onto an SD card and plugged into a
Prusa i3 MK3 3D Printer and executed the print is executedusing PLA filament. Please note: This 3D printer was chosen

5Finalist

3D Printed Origami Cellular Material Switching DOF and Poisson's Ratio
Kanata Warisaya
The University of Tokyo
wari.kan.wari@gmail.com
Asao Tokolo
TOKOLOCOM
info@tokolo.com

Akito Adachi
Seri Nishimoto
The University of Tokyo
The University of Tokyo
adachi.akito.53u@gmail.com serinishimoto@gmail.com
Tomohiro Tachi
The University of Tokyotachi@idea.c.u-tokyo.ac.jp

Hibiki Totsuka
The University of Tokyo
jif.bikilwg10@gmail.com

Main Image

Keywords: origami cellular material, compliant mechanism, multi-stability, auxetics.

1 Background

Hole

Cellular structures constructed by the tessellation of origami
cells have been gaining attention for their special mechanicalproperties such as flexibility and anisotropic stiffness. This typeof structure was explored by artists: ‘Snapology’ by Strobl [1]and ‘BuildVoid’ by Tokolo (fifth author).

P

Solid

S
P

P

Arm

P

S
P

S

P

P

S

P

Our previous study [2] proposed an origami cellular structure
inspired by BuildVoid. Figure 1 shows the composition of thestructure. A module is constructed by connecting four cubic
solids with four pairs of square arms. The module can be folded
into two modes: parallel mode and skew mode, distinguishedby the directions of opposite edges of the quadrangular hole. In
parallel mode, the module has 2 DOFs: folding in x and y
directions are independent. In skew mode, the module has 1
DOF: folding in x and y directions are synchronized. Byarraying the modules in x and y directions, we can construct a
tessellation of the structure. The choice of assignment ofparallel/skew to each module can switch DOF and Poisson’s
ratio of the tessellation (Detailed kinematics is described in [2]).

Parallel

Skew

Figure 1: Composition of the mechanism proposed by [2].
Module (Left) and 4 × 3 tessellation (Right).

3 Modeling

Figure 2 shows a detailed view of a part of the 3D-printed model.
The structure is printed so that all the modules are in skew mode
folded by 𝜋𝜋𝜋𝜋/4. To utilize bending deformation of the material
as hinges, the thickness of the hinge regions 𝑡𝑡𝑡𝑡 must be
sufficiently smaller than that of the other regions, making theratio of bending stiffness ∝ 𝑡𝑡𝑡𝑡 3 sufficiently large. We used 𝑡𝑡𝑡𝑡 =0.75mm. We added a thickness to the solids and the arms witha taper of 45°. This taper is for overhanging, reducing material(also printing time and weight of the structure), and avoiding
collision while folding (Figure 3). The support material
required at isolated boundary edges can be easily removed(Figure 4). We can construct tessellation by repetition.

2 Concept
In this work, we 3D-print the structure with a single material(TPU) as a compliant mechanism. This allows for easierfabrication. Moreover, the structure gets multi-stable, switching
DOF and Poisson’s ratio. This model can be an educational toy
for learning mechanical principles through squeezing it.
6

Finalist𝑈𝑈𝑈𝑈1 = 12 ×Top

𝑈𝑈𝑈𝑈2 = 8 ×

2.5 mm

t

Front
45°

45°

2

2

+4×

𝜋𝜋𝜋𝜋 2= 6𝑘𝑘𝑘𝑘 �𝜃𝜃𝜃𝜃 𝜃 � ,𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑓𝑓𝑓𝑓 22=

4

𝑘𝑘𝑘𝑘(𝜋𝜋𝜋𝜋𝜋12𝜃𝜃𝜃𝜃)224+𝜋𝜋𝜋𝜋2 𝑘𝑘𝑘𝑘
3.

Figure 6 Right shows plots of these functions. 𝑈𝑈𝑈𝑈1 takes theminimum of 0 when 𝜃𝜃𝜃𝜃 = 𝜋𝜋𝜋𝜋/4, which corresponds to theprinted state. 𝑈𝑈𝑈𝑈2 takes the minimum of 𝜋𝜋𝜋𝜋 2 𝑘𝑘𝑘𝑘/3 when 𝜃𝜃𝜃𝜃 =
𝜋𝜋𝜋𝜋/12, which corresponds to the flipped state. The two plots
intersect with 𝑈𝑈𝑈𝑈 = 3𝜋𝜋𝜋𝜋 2 𝑘𝑘𝑘𝑘/8 when 𝜃𝜃𝜃𝜃 = 0. Because this islarger than the minimum of 𝑈𝑈𝑈𝑈2 , the flipped state can be stable.

t

10 mm

𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑘2

𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑘𝑘2

10 mm

Figure 2: Top and front (section) views of a part of the model.

k/4

45°
M=0

k/4
k/4
k/4

Δθ
Δθf

θ
θ

M = k Δθ0°
M = k Δθf

Figure 6: Rigid body and rotational spring model (Left).
Plots of potential energy (Right).

Figure 3: Tapered faces contact together when fully folded.

5 DOF and Poisson’s Ratio

The two stable states of 2 × 2 tessellation have different
DOFs and Poisson’s ratios as follows:(1) Printed state: All the modules are in skew mode, so all therows and columns of the arms are synchronized. This results in
1 DOF and Poisson’s ratio 𝜈𝜈𝜈𝜈 = −1 (auxetic).
(2) Flipped state: All the modules are in parallel mode, so tworows and two columns of the arms are independent. This resultsin 4 DOFs and 𝜈𝜈𝜈𝜈 = 0.

Figure 4: Locations where support material is required (Left).
Removal of support material (Right).

4 Multi-Stability

Due to the elasticity of the material and the half-folded printed
state, the model gains multi-stability; inner arms can be flipped
up and down (Figure 5). To analyze this behavior, we consider
a simplified model where rigid solids and arms are connectedby rotational springs that produce a moment proportional to therotation angle: 𝑀𝑀𝑀𝑀 = 𝑘𝑘𝑘𝑘/4 × ∆𝜃𝜃𝜃𝜃 , where 𝑘𝑘𝑘𝑘/4 is the spring
constant (Figure 6 Left). Strain energy 𝑈𝑈𝑈𝑈 = 𝑘𝑘𝑘𝑘 ∆𝜃𝜃𝜃𝜃 2 /2 is stored
in four springs in the pair of arms. In the flipped state, flipped
arms rotate more than the other arms. Due to the kinematiccondition, the absolute angle 𝜃𝜃𝜃𝜃 between the arm and thehorizontal plane must be equal in all the arms. By using ∆𝜃𝜃𝜃𝜃 =𝜃𝜃𝜃𝜃 𝜃 𝜃𝜃𝜃𝜃⁄4 and ∆𝜃𝜃𝜃𝜃𝑓𝑓𝑓𝑓 = 𝜃𝜃𝜃𝜃 + 𝜋𝜋𝜋𝜋⁄4, we find ∆𝜃𝜃𝜃𝜃𝑓𝑓𝑓𝑓 = 𝜋𝜋𝜋𝜋/2 + ∆𝜃𝜃𝜃𝜃. In
the case of 2 × 2 tessellation, there are 12 pairs of arms, and 4of those can be flipped. Therefore, the potential energy of thetwo modes are

Figure 7: Model compressed in one direction.
Left: printed state (𝜈𝜈𝜈𝜈 = −1), right: flipped state (𝜈𝜈𝜈𝜈 = 0).

6 Software & System

Modeling software: Rhinoceros/Grasshopper
Printer: Qidi X-Pro
Filament: PolyFlex TPU95-HF

References[1] Strobl, H.: Snapology, https://www.snapology.eu/, lastaccessed 2024/05/27.
[2] Adachi, A., Nishimoto, S., Totsuka, H., Warisaya, K.,
Tokolo, A., Tachi, T. (in press): Origami Cellular Material
Switching Between Single and Multiple DOF Modes. 8OSME(2024).

Figure 5: Two stable states of the 3D printed model.
Left: printed state, right: flipped state.
7

Finalist

Curved surface print without support material
1st Author Name
2nd Author Name
Ryo Sakimoto
Chisaki Kitajima
Affiliation
Affiliation
Kyushu University Graduate
Kyushu University Graduate
School of Human-Environment
School of Human-Environment
Studies
Studiese-mail address
e-mail address
sakimoto.ryou.842@s.kyushu-u.ac.jp kitajima.chisaki.218@s.kyushu-u.ac.jp

Keywords: Catenary 3D print, Supportless, Adaptive manufacturing

Abstract

Therefore, we considered modeling using thesuspending caused by gravity[1]. To print a suspending
curve with the targeted height and shape (Figure 1), we
edited the G-code and adjusted the nozzle speed andfilament discharge volume.

Using a rectangular frame shape, when the nozzle of a
3D printer is moved on a planar orbit, the ejectedfilament is suspended, creating a curve similar to acatenary curve. This work controls this curve by editing
the G-code and applies it to a dome-shaped
three-dimensional surface.

1 Concepts and Special Features
One of the challenges of 3D printing using theconventional MEX(Material Extrusion) method is thatthe amount of material used increases due to the need toprint support members in the overhung areas.
On the other hand, when printing without a support
member, sagging occurs, making it difficult to print themodel accurately.

Figure 1: Catenary print method and G-code structure8

Finalist
2 Production Process and Method
In this work, the curve generated when a certain amountof filament ejected from a nozzle moving on a planar
orbit hangs down due to its own weight is considered to
be a catenary curve. PLA (Poly-Lactic-Acid), which iscommonly used in small 3D printers, was used as thefilament material. As shown in the figure, the curve
length L and the amount of slack D of the suspension
curve at constant line density can be expressed from theforce balance equation as follows (Figure 2).

dome-shaped three-dimensional curved surface byweaving the catenary curve as shown (Figure4).
We believe that the error between this experiment andtheoretical values and the accuracy of the injected curve
shape can be more accurately controlled if a precise
deformation analysis of the injection material, PLA,
which has viscoelasticity, can be performed. As a future
prospect, if it becomes possible to accurately form
curved surfaces using this method of utilizing
gravity-induced suspending for modeling, we can
expect to use this method as a substitute for formwork
and reinforcing bars at construction sites.

Figure 2: Definition Formula for Catenary Curves

The E value in the G-code represents the length (mm) of
the filament ejected before it passes through the nozzle
section. In this production, the PLA filament is 1.75 mm(=b) in diameter and the nozzle is 0.4 mm(=a) indiameter. Because the volume of the filament before
passing through the nozzle is equal to the volume after
passing through the nozzle,
Thus, theoretical values (E values) are obtained basedon the curve length L of the catenary curve that we wantto eject.
However, when printing with these theoretical values, it
was difficult to print a catenary curve with the targetedheight. The results are shown below (Figure 3).

Figure 4: The catenary dome model

SoftwareModeling soft: Rhinoceros, Grasshopper
Output device: snapmaker A250T
Filament: iBoss PLAwhite

References
Figure 3: Catenary Printing Experimental Results[1] R. Kinoshita, H. Tanaka, Hanging Print: Plastic

By comparing the experimental values with thetheoretical values, we determined a function to derive
the amount of filament ejection to print a catenary curvewith the targeted height. (α=-15.711, β=1.0281)

Extrusion for Catenary Weaving in Mid-Air,
SIGGRAPH Asia 2022 Posters, No. 53, 2022.

As the final modeling, we succeeded in printing a
9Finalist

A model of the Taj Mahal for tactile and visual recognition
触覚と視覚で鑑賞するタージマハル模型
Kazunori Minatani
1DWLRQDO&HQWHUIRU8QLYHUVLW\(QWUDQFH([DPLQDWLRQV-DSDQ
minatani@rd.dnc.ac.jp

Keywords: The Taj Mahal, Visually impaired, Recognition by touch

1 Overview

視覚障害者である作者は、これまで視覚障害者が 3D
CAD を行う方法と 3D プリンタを操作する方法を研究してきた[1][2]。今回、作者は、触って観察した認識を用いてタージマハルの模型を造形した。つまり、晴眼者が視覚で観察して作った模型を触り、触って理解できる模型を造形した。製作に際しては、元の模型を複製するのではなく、作者なりの造形上の工夫やアレンジを行った。
作者は視覚で観察してもタージマハルと認識されるものと期待している。

A model of the Taj Mahal

2 Production process

Size of the work: 140mm * 140mm * 89mm

In addition, the modeling will be done in parametric CAD
since the author cannot use common GUI CAD software. The
modeling method to reduce obvious errors (simple calculation
errors, typos, etc.) will be applied to a model of the Taj Mahal,
which achieved a high degree of symmetry.

Material: PLA
Year of production of 3D data: 2024
Year of production of model output by 3D printer: 2024
The author, who is visually impaired, has been researching
how visually impaired people can do 3D CAD and operate 3D
printers. This time, he used observation by touch and creates amodel of the Taj Mahal. In other words, he observed a modelthat had been created a sighted person then creates own model
which can be understood by tactile observation. He did not
duplicate the original model, but rather changes with his own
creative arrangements. He expects that the Taj Mahal will bealso recognizable by visual observation.

作者は通常の GUI CAD ソフトウェアを利用できないので、パラメトリック CAD を用いて造形を行った。パラメ
トリック CAD のデータ製作では、自明のエラーが発生しがちである。こうしたエラーを抑制するため、作者は、
今回、最低限要素造形手法を導入した。本手法は、高度の対称性を有するタージマハルに特に有効である。
The generation process from minimal piece to entire model
10

Finalist

Figure 1 :Minimal piece

Figure 2: Mirroring by Y-axis
Figure 4: Rotating by PI/2

Figure 3: Mirroring by X-axis

References

3 Software & System[1] Minatani, K., Finding 3D CAD Data Production Methods
that Work for People with Visual Impairments, HCIInternational 2017 - Posters' Extended Abstracts(HCI 2017),
CCIS Vol. 713, pp. 548-554, 2017.

JScad was used as parametric CAD processor. Source code
was written with Emacs and VS code. Original Prusa MINI
was used for 3D printing in protyping stage then Ultimaker S5
was used in finalizing stage.

[2] Minatani, K., A Practical CAD Method for the Visually
Impaired: A Case of Modeling the Leaning Tower of Pisa,
Universal Access in Human-Computer Interaction (HCII2023), LNCS vol. 14020, pp. 440-450, 2023.

パラメトリック CAD の処理系として JScad を用いた。ソースコードは、Emacs と VS code を用いて記述した。試作の過程では Original Prusa MINI で印刷し、完成したデータは Ultimaker S5 で印刷した。

11

Finalist

I Interactive 3D zoetrope, with manual strobe lights
1st Yoriko Murakami
2nd Kazuhisa Yanaka
Kanagawa Institute of
Kanagawa Institute ofTechnology
Technology
murakami@ic.kanagawa-it.ac.jp yanaka@ic.kanagawa-it.ac.jp

3Ud Hisashi Sato
Kanagawa Institute ofTechnology
sato@ic.kanagawa-it.ac.jp

Keywords: 3D Zoetrope, Interactive strobe lights, Arduino

1. Seeing animation on 3D printed models

as an interface between the virtual 3D landscape and thereal space.

This work Negative Homeostasis is a 3D zoetrope madeby 3D printer output. The work consists of 37 models
arranged on a disk approximately 11 inches in diameter.

2. Model Making

As with any existing zoetrope previously, the models
can be rotated to animate. As the author has abackground in filmmaking, she has previously produced
3D zoetrope animations that are viewed as stop-motion
video, once filmed through a camera lens. However, in
this work, due to a concept, the viewer spins theturntable by hand to create a stroboscopic, for the realtime animated sequence under the strobe lights.

The Model was modeled and animated with 3D CG
program Autodesk Maya. Once the animation was tested
and revised in the program, the model was exported asa .stl file to 3D print. The scale was decided by the of
the diameter of the turn table which made for LP
records size of 12 inch. Each model turned out as short
as an inch of its height due to the limitation of the final
output size.

What this animation represents is a negative loop which
always not too easy to break, such as unhealthy habits,
addiction, or relationships that we are chained to in our
everyday lives.

3. Output Data
Dimensions

This model is a part of VR/MR art installation therefore
was output physically to synchronize with the 3DCG in
the VR space. The strobe light required for the
animation was designed to be triggered by theinteraction with the viewer, as it was intended to be used

PrinterTable 1: Example of Table

280 x 280 x 65(mm)HP Multi Jet Fusion
積層ピッチ：0.08mm

Material12

PA12（ナイロン 12）

Finalist

Figure 1: Sample of a wide figure. Caption (serif font, 9pt, numbered, e.g)

4 Interactive Strobe Lights

References

The speed of rotation of the turn table would notconstant when the turntable on which the model isplaced is rotated manually by an audience. White andblack markers corresponding to the arrangement of themodel were used (specifically, a 12-inch disk with 20
radiation lines printed on it protruding from an 11-inchmodel), and an Arduino infrared sensor was used torecognize the linear markers as a pattern, causing the
LED lights to blink in sync.

1] Simon Stampfer, Jonathan Blower((Translator)) :Stroboscopic Discs: An
Explanation, (2016) , Art in Translation, 8:1,
19-33
[2] Autodesk Maya,
https://www.autodesk.com/[3] Arduino
https://www.arduino.cc/

Figure 3: The strobe system

13Finalist

3D printed Splinter prosthesis socket for forearm amputees
Kosuke Morinaga
Hiroshima International University
sb23314@ms.hirokoku-u.ac.jp

Daisuke Fujii
HIVEC Inc.
fujii-d@hivec.com

Ryota Nonami
National Institute of Technology
r-nonami@kure-nct.ac.jp

Keywords: forearm amputees, splinter, crouching start

1 Backgroundforearm prostheses produced by traditional manufacturingmethods had not been reported. First of all, sockets were
fabricated (Finite Difference Method: FDM) with various 3D
printer filaments and tensile tests were carried out to determine
which filaments had the highest strength (Fig.2). Filaments
made of expensive composite materials did not show stable andstrong strength due to delamination on the lamination surfaceof the filaments. Conversely, filaments of a single material
showed stable strength, although weaker than those ofcomposite materials (Table.1,2). Secondly, the strength of thesockets made by traditional manufacturing methods was
subsequently verified by tensile tests. Three tensile tests werecarried out, with an average value of 1170 N. Then, the stacking
planes are a problem in FDM manufacturing using a single
material, and the strength is not competitive with traditional
manufacturing. For this reason, the Sockets were manufactured
using Selective Laser Sintering (SLS) with Nylon12, which isless likely to separate on the laminate surface. In clinicalpractice, the most frequent breakage is at the anterior edge ofthe socket. Therefore, sockets with a thicker anterior edge of thesocket were also included in the tensile tests (Fig.2). However,as a result, the Nylon 12 sockets were almost as strong as the
traditional sockets, but the sockets with thickened edges were
not as strong as the sockets with thickened edges. Following
these various examinations, it was decided that we would offer
a socket made of ABS, which prints stably and does not cause
discomfort to the user, as both wings of the socket have somedeflection, like a traditional socket. The slight deflection of thesocket also accommodated the circumferential changes caused

This prosthesis user has a congenital forearm deficiency. She
had been interested in short distance running since childhood
and was a member of a local athletics club. Her performance inathletics began to decline in her senior year of primary school.
This is because she has no left forearm and is not able to do the
crouching start with both hands. The lack of a left forearm madeher consider changing sports. Her mother decided to have asplinter prosthesis made, which is not covered by insurance inJapan. The cost of a splinter prosthesis using the traditional
manufacturing method would be 300,000 yen. The problem isthat she is growing and needs to change sockets as often as sheneeds new shoes. The crouching start is important for shortdistance running. A good crouching start requires a proper
socket fit. This project was initiated in order to reduce thefinancial burden and to ensure that the athletes are in the best
possible condition to compete.

2 Points of consideration
The advantages and disadvantages of sockets produced bytraditional methods were first examined. The advantages arethat the sockets are made in a way that has been used for a longtime, so they are safe. The disadvantages are the high cost of
materials, the fact that expensive parts are coated with resin andcannot be reused, and the fact that they are not immediately
resizable and manufactured. To overcome these problems, a 3D
scanner and CAD were used to manufacture the sockets (Fig1).
The strength setting was a problem for the 3D printerfabrication. This was because the strength of sockets for
14

Finalistby the daytime swelling of forearm amputees. The ABS socket
are not as strong as traditional sockets. However, the user wasable to wear the 3D printed prosthetic hand and participate incompetitions without problems. This may indicate that thecurrent strength of prosthetic hands may be overstrength.
Finally, a small change in the volume of the stump could becorrected in CAD and the socket could be remade. The cost of
this 3D printed socket was approximately 900 yen (cost of 3D
printer filament). Furthermore, the expensive parts were notcoated with resin, so the expensive parts could be reused for the
next socket. This manufacturing process could be of great help
to growing amputees.

Fig.2 Left: Values recorded during a large crack in the socket.
Right: Detail of increasing the thickness of the socket edge.

Table1: Tensile test results of sockets (N)
PC-

PC-

PA6-

ABS

FR

CF

350

333

612

290

549

300

365

626

323

633

455

330

583

433

PC

ABS

30%

534

60%
90%
100%

Socket1170

In this table, socket is made by traditional way. This value isthe average of three times.

Table2: Average of tensile test results of NYLON12 sockets(N)
Normal2mm thinker

4mm thinker

1st

1034

1255

845

2nd

1079

1055

645

Average1056.51155

745

Fig.3 Right: Socket is manufactured by, annually soaking theresin into the fabric. This method is labour-intensive and costly.
Left: A finite element method was used on a PC to simulate thestress concentration in the socket.

3 Software & System

Please write your used software and system.
-CAD Software: Autodesk Fusion (Autodesk, Inc.)-FDM: Raise3D Pro2 (Raise3D Technologies, Inc.)-SLS: FUSE1+ (Formlabs, Inc.)

Each NYLON 12 socket produced by SLS was tested twice.
Comparing the normal and 4 mm thickness, the normal isstronger. The results of the tests were not stable for the 2 mm
and 4 mm thicknesses.

Fig.1 Right: traditional plaster moulding. Left: digital mouldwith a 3D scanner. It is digital, corrections can be made on the
CAD.

15

Finalist

Prosthetic Forearm Socket Design
New Possibilities Fusion of 3DCAD and Leather
1st Rentaro Hayashi
Hiroshima International
University
sb23314@ms.hirokokuu.ac.jp

2nd Kosuke Morinaga
Hiroshima International
University
morinaga@hirokoku-u.ac.jp

3rd Daisuke Fujii,
HIVEC Inc.
fujii-d@hivec.com

4th Atsushi Kamatani
Hiroshima International
University
sb23307@ms.hirokokuu.ac.jp

Keywords: Boxel, leather, socket

1 Reversed thinking

Conventional prosthetic hand sockets have
many constraints in their production. Whenleather is incorporated into conventional
prosthetic hand sockets, it is not possible todesign freely and the inherent appeal of leather
cannot be utilised. However, the incorporation of
3D printing creates a degree of freedom in socket
design.The flexibility, plasticity and ageing
properties of leather allow the complex shapes of
3D printers to be adapted and new possibilities
to be pursued.
A voxel-shaped prosthetic hand socket, whichcannot be produced with conventional prosthetic
sockets, was produced. Voxel shapes and leather
were chosen to express the fusion of digital andanalogue.

Current prosthetic arms and legs face thechallenge that they are difficult to design freely.
This is because restrictions in the insurance
system and manufacturing process limit thedegree of freedom of design. In this study, we
attempted to produce a socket for a prosthetic
hand, making use of our knowledge of spatialconfiguration and form design developed in the
Department of Architecture.
The sockets produced were designed from new
perspectives, such as the use of 3D CAD toenable low costs despite their complex shape,
and to allow the prosthetic hand to experience
the warmth of the texture and the change overtime of the leather. The aim is to add new
perspectives to the conventional prosthetic handto create a fashonable prosthetic hand.

16

Finalist

Photo 1.

BOXEL
When blending with leather, aMaking use of the plasticity of leather Making thestreamlined 3D model (general 3D model), themost of its greatest strength voxel Perfect

Leatherand resin

adhesion between leather and resin, Complete

leather's original the natural characteristics offully adherent

adhesion between leather and resin Express

leather could not be utilized to the fullest.

voxels from expression to feel. Aiming at the fusion

Flexibility, plasticity and ageing. Voxel is usedof resin (3D model) and leather Adopts the quilt of

to take advantage of flexibility, plasticity andTwo curtain-likeleather shoes

ageing. Fusion with leather Fixed concept ofexpressions are

Means to keep out mud and dust. Use as design

3D printers and lead to a rethinking of thevisibleExaggerate the design with holes and threads Low

stereotypes of 3D printing. Reverse thinking tocenter of gravity Wrapped around a metal platefind the essence of things. To invite theAccelerates the swing of the arms and aids

viewer's questions and evoke a range ofrunning.

Representing thetrue expression ofemotions and feelings.

Photo 2.

voxel

2 The process of integrating leather and 3D.
modelsPhoto 3.

The voxel shape from the conventional prosthetic hand socket
shape has increased the number of variations of leather andsocket combinations.
Therefore, leather was applied to the voxel-shaped socket tocheck the texture of the leather (Photo 4). As shown in Photo

normal socket
Photo 4.

4, the 3D model with leather attached lacked a sense ofvoxel socket

massiveness and stylishness.

Photo 5.

In addition, the voxels in the upper half of the model were
hidden from view by the leather. In this work, the leather
parts were separated one by one in order to give the feelingthat the leather blends in with the voxel-shaped socket. This
allows the leather and socket to become one piece, giving amore natural look and feel. It also improves the close fit

Boxel socket with leather attached.

between the leather and the 3D model, giving it a more three-Re-made stencils.

dimensional and stylish appearance.

3 Software & System
Fusion（Autodesk）
Anker Make (Anker)

4 Size of work
73 x 74 x 154 (mm)5 Material

Pla resin

6 Years of creation of 3D data
2024

7 Production of 3D printed models
2024

17

Objects

Design of prosthetic forearm sockets
New possibilities by combining 3D CAD
and leather

Photo 1.

Voxel socket idea sketches

Photo 2.

normal socket

Photo 3.

voxel socket

Photo 4.

Boxel socket with leather attached.

Photo 5.

Re-made stencils.

Finalist

A study for tessellation with motif of Escher
Masaki Koyama
Hosei University
Graduate School of Engineering and Design
Major in Architecture
masaki.koyama.2v@stu.hosei.ac.jp

Naomi Ando
Hosei University
Faculty of Engineering and Design
Department of Architecturen-ando@hosei.ac.jp

Keywords: 3D tessellation, M.C. Escher, Box Stacking

1 Introduction

we created a model that would work as an architecture even if
it was flipped upside down if there was no gravity. As a result,
this model expresses the visual confusion that Escher depicted.
In addition, since it can be used in low gravity or zero gravity,
it can also be used as an architectural proposal for humanhabitation plans in space development which has been actively
carried out in recent years.

M.C. Escher (1898-1972) depicted many pictures in which
unique geometric patterns to tessellate 2D surfaces and express
illusions. Many of Escher's paintings are so mysterious that theycannot be formed as 3D objects, even though they can bedepicted as 2D figures. However, there are some paintings inwhich he seems to have attempted to tessellate a 3D space. In
addition, these paintings have a common feature in that they do
not define the direction of gravity, so it is making this form
possible within the painting.

2 Production ProcessThis work is a 3D model output at a scale of 1:300 of a structure
within a volume of 30000x30000x30000 mm. Five boxes withdimensions of 5000x5000x10000 mm were placed randomly on
the ground floor. Additional boxes with the same dimensions
were stacked on the upper floors, and stairways were added toConsidering this point, we created this work as a containershaped box that can infinitely tessellate 3D space. Although it
has an architectural form in which the boxes are physicallystacked, by adding stairways inside that connects all the boxes,

18Finalist

Figure 1: Internal SpaceIn this 1/300 scale model, the stair steps are modeled 1 mm in depth, 1 mm in height, about 10 mm width.

Figure 2: Rotation of Structure
Since the front and back side of stairways are accessible, they work at all angle as a building.
They do not only define the direction of gravity, but also represent tessellation of 3D space of Escher.
structure was modeled by randomly stacking container-shapedboxes. A Python script was utilized to place a designatednumber of boxes on the ground level and to stack additional
boxes. Subsequently, we used SketchUp, another 3D modelingsoftware, to add stairways connecting the boxes. Our model
was completed in a month conclusively.

connect the boxes (Figure 1). The sloping angles of thestairways were set to 45 degrees, allowing the stairways to be
used even if the structure is rotated 90 degrees or placed upside
down (Figure 2).
Regarding the printout of this model, we requested an external
output service company and selected acrylic material which is
toughness and rigidity, named AR-M2, which was output by
AGILISTA.

References[1] Locher, J. L., M. C. Escher: His life and Complete Graphic
Work, メルヘン社, Translated by Itsuo, Sakane, Japaneseedition, 1995.

3 Software & System

We used Rhinoceros, a 3D modeling software, along with
Grasshopper, a programming plug-in tool for Rhinoceros. The

19