情報処理学会 インタラクション 2021
IPSJ Interaction 2021

2P05
2021/3/10

An omnidirectional shape-changing bubble display
Zhao Juejian1

Kazuki Nambata2

and Toshiki Sato1

Abstract: We present a novel spherical display that utilizes a bubble as a screen material. This device canquickly generate soap bubbles as the screen. Since the generated bubbles are initially transparent and fragile,
we propose a technique such as rapid freezing to ﬁx the bubble and enable image projection. In this paper,
we propose the ﬁrst prototyping method and some application ideas such as an instant spherical screen or
remote presence display by taking advantage of the deformability and rapid generation/bursting capabilityof the bubble.

1.

Introduction

The spherical display can display in all directions whileallowing users to touch and interact. It will have completely
diﬀerent applications and interaction methods depending on
the size and shape of itself. For example, when the display
is small, it is suitable for a single user to browse and operate it with both hands [1], while a large spherical display
can be used by multiple people to communicate with eachother around it [2]. However, the shape and size of the traditional spherical display cannot be changed. The numberof applications that can be realized on a single display islimited.
Therefore, we decided to propose a deformable sphericaldisplay, which can quickly change the size and shape of thedisplay surface to adapt to more content and applications
Figure 1. To make a deformable spherical screen, the material of the screen is the most important thing to consider.
The material to form the sphere must be ﬂexible, varying
smoothly from ﬂat to spherical, and could be ﬁxed in any
shape and size as needed. Also, the surface of the sphereshould diﬀuse the projector light.
Therefore, this research proposes to use ”bubble” as thescreen. We believe that the bubble has the following advantages and potential. The bubble is ﬂat before forming, andwhile it expands, it will go through a change from becoming
hemispherical to spherical, which can freely switch between
two-dimensional and three-dimensional and change the sizeof the display surface.
However, it is still diﬃcult to use the bubble as a screen
to project images from a projector because of its high transparency. This research ﬁrst explores a method for dynamically controlling the transparency of sphere-shaped bubbles,such as ultrasonic, rapid cooling, etc. At the same time,
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JAPAN ADVANCED INSTITUTE OF SCIENCE ANDTECHNOLOGYThe University of Electro-Communications© 2021 Information Processing Society of Japan

it can also realize some unique interactions because of therapid generation and bursting of bubbles. For example,
the following ”instant spherical screen” could be realized.
Users can blow up the bubble on the projector lens whenneeded and instantly create a spherical display of any sizeand shape. When it is no longer needed, it can be immediately destroyed and returned to a normal projector.
In this research, we prototype a spherical bubble display platform with the unique capabilities described above,
studying smooth video transitions between spherical displays of diﬀerent sizes/shapes and input motions suitablefor use on dynamic soap bubble screens. Besides, we propose applications that take advantage of bubbles to validate
the unique interaction elements such as shape-changing anddestructible omnidirectional projection, touch interaction,
and artistic projection, etc which achieved by our system.

2.

Related Work

The Poppable display [3] utilizes transparent soap bubbles
as a projector light diﬀuser by vibrating it with ultrasonicwaves. In this research, we will investigate the application ofits method, and we will also consider the methods of coolingand freezing the soap bubble and chemically hardening thesoap bubble. By hardening the soap bubble surface, we believe that it will be possible to interact by directly touchingit, which has not been possible in previous studies.
Balloonygen [4] is a spherical display that can dynamically change shape by using rubber balloons. By controlling
air pressure, Balloonygen can produce a spherical display of
any size from a ﬂat surface. Although this study is the previous research of our study, the most signiﬁcant diﬀerence
from our proposal is the transparency and renewability. The
bubble used in our study is normally transparent, and thescreen can be quickly eliminated and rebuilt by destroying
and generating bubbles. Although transparency is a disadvantage of the screen, the projector can project forward asusual while the bubble is transparent or not yet inﬂated. We678

情報処理学会 インタラクション 2021
IPSJ Interaction 2021

2P05
2021/3/10

Fig. 2

5.
Fig. 1

Hardware conﬁguration

develop a new interactive display that takes advantage of thedynamic change in transparency of the spherical screen andthe immediacy of the creation and destruction of the bubble.

3.

Proposal Method

This research focuses on the interactivity of the bubble
and considers the properties of it, which can produce different interactions under diﬀerent conditions. First of all,the primitive bubble has high deformability, but it cannot
be projected because of the transparency and will break if
touched. In this case, we consider using ultrasound to vibrate so that it can be projected. At the same time, users
can also control the size of the bubbles and perform some
simple interactions through speciﬁc items such as straws.
Also, because it can be quickly generated and destroyed,
users can use this feature as an input interaction.
Considering the interactivity brought by touch, we think
it is necessary to make bubbles that can be touched. We propose to use freezing to make the soap bubbles hard and able
to be projected. Under this condition, the size of the soap
bubble will be ﬁxed once it is generated, and it has a certain degree of hardness, allowing users to touch and interact
with it. Besides, we also consider adding other ingredientsto the soap liquid or using thermoplastic material as raw
material to change the transparency or hardness of the generated bubbles. This method also has diﬀerent interactions
according to the diﬀerent materials of the generated soapbubbles. In the prototype design, we will focus on freeze thebubble and the construction of the cooling system.

4.

Prototype Design

The system conﬁguration is shown in Figure 1. This system consists of three parts, namely the projection system,
the screen generation system and the bubble control system.
The projection system consists of a projector and a camera,
and is responsible for detecting the shape generated by thescreen system and performing omnidirectional projection.
The bubble generation system is responsible for producing
soap bubbles. Regarding the bubble control system, our research mainly proposes to study a rapid cooling system toharden the bubbles. The constitution of the cooling system
is shown in Figure 2. We plan to use multiple peltier devices
to celerity freeze the bubble so that it can be projected. The
structure of the peltier device is shown in Figure 2.

© 2021 Information Processing Society of Japan

Rapid cooling system and Peltier device

Application ideas

The proposed system can realize spherical screens of various sizes and shapes, and at the same time, it can be applied to the following applications that take advantage ofthe rapid ”expansion”, ”hardening”, and ”destruction” ofbubble screens.
The ﬁrst is an application in which, when the user presses
a button, an omnidirectional screen capable of touch input
is rapidly formed in front of the projector lens, allowing theuser to operate the menu at hand. At this time, the user canreturn to normal projection by simply destroying the screen
when the operation is ﬁnished.
Second, the proposed system is capable of expressing theentire process of shape change by gradually feeding air into
the soap ﬁlm, from ﬂat to hemispherical to spherical, andﬁnally breaking (or ﬂying). By projecting interactive images that reﬂect the user’s touch and the explosion of soap
bubbles on this process, we believe that it will be possible
to express the beauty and fragility of soap bubbles.
Finally, we believe that the system can be used as a display to present the ”presence” of the other party by projecting the other party’s head onto a soap bubble at handduring a remote conference. In this case, the user would beable to inﬂate and sometimes explode the size of the display showing his or her own face in the other person’s hand.
This would allow the user to express emotions such as ”excitement” and ”joy” that are diﬃcult to convey with theconventional ”clap” button.

6.

OutlookAs the next step, we intend to develop portable models based on prototypes to meet more application scenarios. Also, to explore better control methods for projecting
on bubble surface and ﬁnd better quality ingredients of thebubble. Besides, we also plan to develop new input methods
other than break the bubble.
References
[1]

[2]

[3]

[4]

Hrvoje Benko, Andrew D.Wilson, and Ravin Balakrishnan.
Sphere: multi-touch interactions on a spherical display. In
Proceedings of the 21st annual ACM symposium on User interface software and technology, pp. 77–86, 2008.
Nikita Soni, et al. Adults’ and children’s mental models forgestural interactions with interactive spherical displays. In
Proceedings of the 2020 CHI Conference on Human Factors
in Computing Systems, pp. 1–12, 2020.
Yoichi Ochiai, et al. Poppable display: A display that enables
popping, breaking, and tearing interactions with people. In
2013 IEEE 2nd Global Conference on Consumer Electronics(GCCE), pp. 124–128, 2013.
Soichiro Toyohara, et al. Balloonygen: extended tabletop display embedded with balloon-like deformable spherical screen.
In Proceedings of the 24th ACM Symposium on Virtual Reality Software and Technology, pp. 1–5, 2018.

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