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Soft swimming: exploiting deformable interfaces for low reynolds number locomotion
Renaud Trouilloud1, Tony S Yu, A E Hosoi
1Hatsopoulos Microfluids Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Physical Review Letters
|September 4, 2008
Summary
Reciprocal motion enables locomotion near deformable interfaces, overcoming limitations in viscous fluids. This strategy uses flow-induced deformations to rectify movement, allowing swimmers to navigate interfaces.
Area of Science:
- Fluid dynamics
- Soft matter physics
- Biophysics
Background:
- Locomotion at low Reynolds numbers typically relies on non-reciprocal motion.
- Reciprocal movements are generally ineffective for propulsion in viscous fluids or near rigid boundaries.
Purpose of the Study:
- To investigate if reciprocal motion can achieve locomotion near a deformable interface.
- To identify the mechanisms and conditions enabling such movement.
Main Methods:
- Theoretical analysis using physical arguments and scaling relationships.
- Investigating nonlinearities from flow-induced interfacial deformations.
- Conducting macroscale experiments with flapping motion near a free surface.
Main Results:
- Reciprocal motion near a deformable interface can lead to locomotion.
- Interfacial deformation rectifies the swimmer's periodic motion.
- Movement is possible towards, away from, and parallel to the interface.
Conclusions:
- Deformable interfaces enable locomotion via reciprocal motion, a previously unachievable feat.
- The findings introduce a new strategy for microswimmers operating near soft boundaries.
- This work highlights the importance of fluid-structure interactions in low Reynolds number locomotion.
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