Researcher Information


Associate Professor

Enjoying science of “Active Matter”!

Department of Chemistry, Physical Chemistry


“Active matter” belongs to group of materials which can produce motion by converting their own chemical energy. As the result active maters can autonomously perform work without any external support. This feature of active matter makes them different from any other materials. Through understanding the science of active matter, we are aiming to improve the quality of our life by solve existing problem for example energy and medical sectors.

FieldPolymer Chemistry, Biophysics, Softmatter Physics, Biomaterial Mechanics

Introduction of Research

Engines and electric motors have brought a great advancement in human civilization. However, for the sake of environmental protection and sustainable development there a growing demand of renewable and clean energy. To address this demand, we have been focusing on active matter derived from nature, biomolecular motors. Biomolecular motors can convert chemical energy into motion with a high efficiency (~ 80%) and specific power (20 times higher than that of conventional electric motors). We believe these advantages of biomolecular motors will help invent new technologies for sustainable development.

1) Swarming of active matter
Birds, fish, cells, and bacteria form “swarm” without necessity of a leader. Depending on their environment, they change shape and size of swarm. Swarms are capable of accomplishing tasks, which is not achievable by single individual organisms. Recently, by using a self-driven biomolecular motor, we have succeeded in reproducing swarming in laboratory condition. We also successfully controlled the movement of the swarm by applying physical stimulation (Figures 1 and 2). Studying the swarming of active matters will be beneficial for developing drones and cars that will be able to move autonomously.

2) Active molecular probe
By utilizing the characteristics of the self-driven biomolecular motors, we have developed new technology that can detect surface deformation of soft-matters, which has been challenging so far (Figure 3). Soft matter has been attracting attentions in recent years in many fields such as medicine and electronics. Our technology will provide new method for characterizing surface properties of soft matters.

3) Molecular swarm robot
We have developed molecular robots incorporating all three necessary components, sensor, actuator, processor. The developed molecular robots autonomously swarm in response to chemical (DNA information) and physical signals (light information), which will pave a way for developing smart nano-machines in future (Figure 4).

4) Artificial molecular muscle
Through fusion of a biomolecular motor synthesized by biotechnology and a DNA nanostructure (DNA origami) synthesized by DNA nanotechnology we have succeeded in developing an artificial molecular muscle. The artificial molecular muscle exhibit dynamic contraction like smooth muscle (Figure 5). This invention will serve as new type of power source for microrobots in the future.

Figure 1: Demonstration of swarming in laboratory condition
Figure 2: A simple way to control swarming molecular machines
Figure 3: Active molecular probe for detecting surface deformation of soft-matters
Figure 4: Molecular robots swarm like birds
Figure 5: Artificial molecular muscle contracts with chemical energy

Representative Achievements

"Adaptation of Patterns of Motile Filaments under Dynamic Boundary Conditions"
Daisuke Inoue, Greg Gutmann, Takahiro Nitta, Arif Md. Rashedul Kabir, Akihiko Konagaya, Kiyotaka Tokuraku, Kazuki Sada, Henry Hess, *Akira Kakugo, ACS Nano, (2019)
“Artificial Smooth Muscle Model Composed of Hierarchically Ordered Microtubule Asters Mediated by DNA Origami Nanostructures”
Kento Matsuda, Arif Md. Rashedul Kabir, Naohide Akamatsu, Ai Saito, Shumpei Ishikawa, Tsuyoshi Matsuyama, Oliver Ditzer, Md. Sirajul Islam, Yuichi Ohya, Kazuki Sada, Akihiko Konagaya, *Akinori Kuzuya, *Akira Kakugo, Nano Letters, 19 (6), 3933-3938 (2019)
“DNA-assisted swarm control in a biomolecular motor system”
Jakia Jannat Keya, Ryuhei Suzuki, Arif Md. Rashedul Kabir, Daisuke Inoue, Hiroyuki Asanuma, Kazuki Sada, Henry Hess, Akinori Kuzuya, *Akira Kakugo, Nature Communications, Vol. 9 (453) (2018)
“Sensing surface mechanical deformation using active probes driven by motor proteins”
Daisuke Inoue, Takahiro Nitta, Arif Md. Rashedul Kabir, Kazuki Sada, Jian Ping Gong, Akihiko Konagaya, *Akira Kakugo, Nature Communications, 2016, Vol. 7:12557 (2016)
“Formation of Well-oriented Microtubules with Preferential Polarity in a Confined Space under a Temperature Gradient”
Akira Kakugo, Yoshiki Tamura, Kazuhiro Shikinaka, Momoko Yoshida, Ryuzo Kawamura, Hidemitsu Furukawa, Jian Ping Gong, J. Am Chem. Soc, 131 (50), 18089-18095 (2009)
Academic degreePh.D.
Self Introduction

I have been fascinated always by the beauty of natural flocking exhibited by living organisms, such as groups of birds, schools of fish, etc. In the early stage of my career I came across critical roles of tiny self-propelled biomolecular motors in cell movement, muscle contraction etc. in living beings. Being motivated by the functions of biomolecular motors I have investigated mechanism behind conversion of chemical energy into kinetic energy by biomolecular motors. During my doctoral study I fabricated world’s smallest power device by assembling biomolecular motors. Recently I successfully demonstrated swarming in laboratory conditions using self-propelled biomolecular motors. I am now aiming at developing molecular robots in which driving force of the robots will be generated by swarms of biomolecular motors.

Academic background2003 Doctor of science degree Graduate School of Science, Hokkaido University
2003 Research Assistant, Graduate School of Science, Hokkaido University
2004 Research associate, Graduate School of Science, Hokkaido University
2008-2011 PRESTO Researcher, Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST)
2011-present Associate Professor, Graduate School of Science, Hokkaido University

2007-2009 Tokyo University of Agriculture and Technology Lecturer (part time)
2014-2014 Kyusyu University Lecturer (part time)
2017-2018 Columbia University Visiting Researcher
2019-2019 Tokyo Institute of Technology Lecturer (part time)
2019-2020 Fukuoka University Lecturer (part time)
2019-2020 Osaka University Lecturer (part time)
Affiliated academic societyThe Society of Polymer Science, Japan,
The Biophysical Society of Japan,

Materials Research Society of Japan,

American Chemical Society
ProjectMolecular Engine: Design of Autonomous Functions through Energy Conversion
Molecular Robotics
Room addressScience Building 7-215

Department of Chemistry, Physical Chemistry


Associate Professor

What made you decide to become a researcher?

“Movement of non-living things utilizing their own power source” triggered vast curiosity in my mind with utter sensation. Fortunately, I was able to be involved in the research of such active materials (active matter), and I am still immersed in that research.

What is your dream that you want to achieve through your research?

I have always been fascinated by ‘Flocking’ in nature. Flocking is exhibited not only by birds and fishes, but sometimes we can also demonstrate flocking. However, what we have no clear idea about is the reason behind flocking. How and why do you create a “flock”? I would like to find answers to these questions by using active matter (molecules) that are not living organisms but can move on their own. If these questions are answered, it will take us a way to develop molecular sized swarming robots and offer emergent functions.

Illustration of active matter (left), me observing active matter through a microscope (upper right), microscope image of the active matter (lower right)
Please introduce a major project that you are tackling on.

A new academic research project named “Creation of molecular robots with intelligence and sense”, a grant-in-aid for scientific research (2012-2017), has been recently successfully implemented. This project aimed at developing amoeba-type molecular robots using active matter that can move on their own. Then, a successor project of the amoeba-type molecular robot was sponsored by New Energy and Industrial Technology Development Organization (NEDO) Next-Generation Artificial Intelligence and Robot Core Technology Development Project (2016-2020). Through this project, molecular artificial muscle composed of active matter has been successfully developed. Currently, a new academic area research project named “Molecular Engine” (2018-2022) is ongoing to extract energy and information from active matter.