Undergraduate and Graduate Schools

Home > Undergraduate and Graduate Schools > Faculty Members List > Department of Mechanical Engineering > Azusa Kage

Azusa Kage

Affiliation Department of Mechanical Engineering
Title Assistant Professor
Fields of Research Gravitational biology; Cell motility
Degree Ph.D. in Biology (Ochanomizu University)
Academic Societies Zoological Society of Japan; Biophysical Society of Japan
E-mail kage@me
Please append "" to the end of the address above.
Laboratory website URL
Researcher information URL(researchmap) Researcher information


I have been working on gravitational biology and collective dynamics of swimming microorganisms living in low Reynolds number comditions.

Theme1:Mechanics of gravi- and rheoresponse in swimming microalgae


Microalgae are primary producers in nature. Some swimming microalgae such as Euglena, Chlamydomonas and Volvox have been used by biologists as model organisms for investigating important biological processes, e.g. photosynthesis and motility. They swim with thin hair-like structures called cilia or flagella, of which diameter is about 200 nm, and show directional movement to external stimuli such as light (phototaxis) or gravity (gravitaxis). In order to understand how they move in sub-millimeter scale, mechanical as well as physiological approach is essential. We particularly focus on responses to gravity and flow in Chlamydomonas, a unicellular, biflagellated green alga, that is a leading model organism for studying eukaryotic flagella and a "ready-made" puller-type microswimmer.

Selected publications and works

Chiharu Hosoya, Asuka Akiyama, Azusa Kage, Shoji A. Baba, Yoshihiro Mogami, Biological Sciences in Space, 24: 145-151, 2010.


Low Reynolds number; microswimmer; gravitaxis; mechanical stimuli

Theme2:Collective motion of microorgamisms

Bioconvection of Chlamydomonas reinhardtii, the wild type and flagellar mutants. (see Kage & Mogami, 2015)

Bioconvection, a class of collective motion, occurs in suspensions of swimming microorganisms. It was named "bio"convection because of its similarity to other convective phenomena, particularly to Reyleigh-Benard convection by appearance. Bioconvection is distinguished from other convective phenomena by that the particles in the fluid are active and self-propelled; they are different from passive tracer particles and their movements cause bioconvection. We aim to understand this collective motion in terms of the underlying hierarchy: from molecules to individual motility, from individual motility to collective motion.

Selected publications and works

Azusa Kage and Yoshihiro Mogami, Zoological Science, 32: 396-404, 2015.
Azusa Kage, Chiharu Hosoya, Shoji A. Baba, Yoshihiro Mogami, The Journal of Experimental Biology, 216, 4557-4566, 2013.
Azusa Kage, Eriko Asato, Yoko Chiba et al. Zoological Science, 28: 206-214, 2011.


Collective motion; flagella/cilia; biofluid; active matter

Title of class

Experimental Practice for Mechanical Engineering (B11610021); Creative Experiment for Mechanical Engineering (B11610103); Physics Laboratory (B1013009a)

Others (Awards, Committees, Board members)

[Honors and Awards]
- 2nd place in the Fluids Category Poster Competition, American Society for Gravitational and Space Research (2012)
- Yasui-Kuroda Scholarship, Ochanomizu University (2012)
- Zoological Science Award and Fujii Award, Zoological Society of Japan (2012)

to Page top