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Published on: January 28, 2020
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Deformation of a micro-torque swimmer
Takuji Ishikawa1, Tomoyuki Tanaka1, Yohsuke Imai1
1Department of Bioengineering and Robotics , Tohoku University , 6-6-01, Aoba, Sendai 980-8579, Japan.
Proceedings. Mathematical, Physical, and Engineering Sciences
|March 22, 2016
Summary
Ciliate cell deformation, influenced by membrane tension and gravity, affects swimming behavior. Numerical simulations reveal how cell shape changes and impacts upward/downward movement, offering insights into physiological responses.
Area of Science:
- Biophysics
- Fluid dynamics
- Cell biology
Background:
- Membrane tension is hypothesized to regulate ciliate swimming velocities.
- The deformation and membrane tension of ciliates remain incompletely understood.
- Understanding these properties is crucial for ciliate physiology.
Purpose of the Study:
- To numerically investigate ciliate deformation during free swimming.
- To explore the influence of membrane elasticity, cell shape, and density difference on deformation.
- To analyze the effect of gravity on membrane tension and swimming behavior.
Main Methods:
- Modeled the ciliate cell body as a capsule with a hyperelastic membrane.
- Simulated thrust forces using distributed torques above the cell body.
- Investigated effects of capillary number, aspect ratio, and density difference.
Main Results:
- Ciliate cells deformed into a heart shape at high capillary numbers.
- Gravity altered membrane tension: decreasing at the anterior end during upward swimming and increasing during downward swimming.
- Gravity-induced deformation led to geotaxis-like behavior (downward or upward movement).
Conclusions:
- Ciliate deformation is significantly influenced by membrane properties and external forces like gravity.
- The study provides a physical explanation for geotaxis-like behavior in ciliates.
- Findings enhance understanding of ciliate responses to mechanical stimuli and environmental factors.
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