A Pixel-Free Display Using Squid's Chromatophores
Juppo Yokokawa
Graduate School of Design, Kyushu
University 2DS18079Y@s.kyushu-u.ac.jp

Haruki Muta

Ryo Adachi

Hiroshi Ito

Kazuhiro Jo

Graduate School of Design,
Kyushu University
intrjctn@gmail.com

Graduate School of Design,
Kyushu University
mumanddad6660816@gma
il.comFaculty of Design, Kyushu
Universityhito@design.kyushu-u.ac.jp

Faculty of Design, Kyushu
University / YCAM
jo@jp.org

Abstract
In this ongoing project, we propose a pixel-free
display using a squid's chromatophores. Thesquid's body surface has cells which contain apigment called chromatophores. Instead ofusing pixels of standard visual displays, westimulated the chromatophores of a squid bysending sound signals of accompanied music to
its body through electronic probes and made anexperimental music video.

chromatophores by sound signals and shot ourexperiments as a music video.
2.

Related work

Backyard Brains Inc. introduces an experiment
to stimulate chromatophores by sound signals
from iPod. [3] Based on the trial, we measured
Chromatophore’s frequency response (Fig. 1).
[4]

1. Introduction
Our daily lives are surrounded by various typesof visual displays, such as computer monitors,
smart phones, projectors, VR headsets etc. The
information carried by them varies depending on
the applications or purposes such as videos,news, slides, games, etc.
However, almost all of the displays are thesame in that they are composed of pixels. Evenin the case of computational “generative” art
like biological simulation, it is inevitable tocompute and render an image by pixel unit. [1]In this project, we consider squids as analternative display free from pixels. The squid's
body surface has cells which contain a pigment
called chromatophores. [2] The squid freelychanges its body color by changing the size ofthe pigment with electric signals from nerve
cells to the chromatophores. To take advantage
ofthesefeatures,
westimulated

Fig. 1. The area of chromatophore per frequency [4]Based on the experiments, we seek a best
relationship between chromatophores and soundsignals in a form of music.
3.

Our approach

3-1. SoundAs a preliminary experiment, we first explored
how chromatophores respond to sound signals.
We attached a copper needle to a sound cableas an electronic probe and directly produced
sound signals from a computer into the surface

of a fresh squid (Fig. 2). The result showed thatthe lower frequencies (i.e., the bandwidth ofdrum and bass) cause a higher effect to thechromatophore.

Fig. 3. Footage form a music video

Fig. 2. Setup of the experiment.

To make music (i.e., sound signals)
appropriate to the squid, we finely generated
waveforms of the music (i.e., sound signals)
with a numerical programming environment,
MATLAB, by checking the effectiveness withdifferent arrangements. We generated eachwaveform with MATLAB, and arranged thewaveforms in a form of music with standard
music production software Ableton Live10.
3-2. Shooting
We shot our experiments by Canon 60D withCanon EF-S 35mm f/2.8 Macro IS STM. We
shot several footages by changing thestimulation point of the squid with the samemusic. After the shoot, we edited the footages
by Adobe Premiere Pro CC 2018. To keep theconsistency between the sound and the display,
we limited our edits to cutting, masking, andsubtle color grading.
4.

ResultAs a result, we made a music video as one
application of the pixel-free display using thesquid's chromatophores (https://youtu.be/66RoX2h8aI ). The duration of the video is 2min45sec, and the resolution is 1080p (Fig. 3).

Even though display successfully escapedfrom the use of pixels, the video itself remainedin pixel form. Therefore, as future work, weplan to show the display in real time as theform of live performance.
Acknowledgements
This work was supported by JSPS KAKENHI
Grant Number JP17H04772.
References
1. Hartmut Bohnacker, et al. Generative
Design: Visualize, Program, and Create withProcessing (2012).
2. R.A. Cloney, and E Florey. Ultrastructureof cephalopod chromatophore organs. Cell andTissue Research 89, (1968) : 250-280
3. Backyard Brains, “Insane in the
Chromatophores,” (2012).
http://blog.backyardbrains.com/2012/08/insan
e-in-the-chromatophores/.
4. Ryo Adachi. 2017. “Frequency Response ofChromatophores to Electrical stimuli in
Uroteuthis edulis.” Bachelor thesis, School ofDesign， Kyushu University. (in Japanese).
Biography
Juppo Yokokawa is in the 1st year of a Master’s
degree in Graduate School of Design, Kyushu
University. He has received the Bachelor invisual communication design from the Schoolof Design, Kyushu University in 2018. His
research interests include media art, especiallybio art and kinetic art, under the supervision ofKazuhiro Jo.