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Microscale Hydrodynamic Cloaking and Shielding via Electro-Osmosis.
Evgeniy Boyko1,2, Vesna Bacheva1,3, Michael Eigenbrod4
1Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa, 3200003 Israel.
Physical Review Letters
|May 21, 2021
Summary
Researchers can cloak objects in microscale flows by injecting momentum, making the flow field outside unaffected. This method also allows for shielding, eliminating hydrodynamic forces on the object, with dynamic state switching demonstrated.
Area of Science:
- Fluid dynamics
- Microfluidics
- Acoustic cloaking
Background:
- Microscale flows present unique challenges for manipulating objects and their surrounding fluid dynamics.
- Hydrodynamic forces can significantly impact the behavior and stability of microscale objects.
- Controlling flow fields around objects is crucial for various microfluidic applications.
Purpose of the Study:
- To theoretically and experimentally demonstrate momentum injection for flow control around microscale objects.
- To achieve "cloaking" (unaffected external flow) and "shielding" (eliminated hydrodynamic forces) conditions.
- To present a versatile method applicable to various object geometries.
Main Methods:
- Utilizing field-effect electro-osmosis for controlled momentum injection.
- Developing a theoretical framework with analytical solutions for different shapes.
- Performing numerical simulations and experimental validation.
- Demonstrating dynamic switching between cloaking and shielding states.
Main Results:
- Successful theoretical and experimental demonstration of momentum injection for flow manipulation.
- Achieved cloaking conditions where the external flow field remains undisturbed.
- Achieved shielding conditions, completely eliminating hydrodynamic forces on the object.
- Validated the dynamic switching capability between cloaking and shielding states.
Conclusions:
- Momentum injection via field-effect electro-osmosis offers a novel approach to control microscale fluid dynamics.
- This technique enables the dynamic cloaking and shielding of objects in microflows.
- The findings have potential applications in micro-robotics, particle manipulation, and advanced microfluidic devices.
