light control of phototactic microswimmer suspensions connor hann, danielle riggin, janan zhu duke...
TRANSCRIPT
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Light Control of Phototactic Microswimmer Suspensions
Connor Hann, Danielle Riggin, Janan ZhuDuke University
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How Does Light Affect Algal Motion?
(
200 Hz Camera
LightSource
Red Light (Filter)
Microscope
Flow
1 mm
1 mm
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Flow at Low Speeds Creates Layers of Different
Velocities
z
This type of flow is called Poiseuille Flow.
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Chlamydomonas Moves in Response to Light
Eyespot
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Visualizing Algal Flow
(
200 Hz Camera
LightSource
Red Light (Filter)
Microscope
Flow
1 mm
1 mm
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Light Orientation Determines Direction of Motion
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Light Alters Swimmer Movement
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Mathematical Model Matches Data
Dis
tanc
e fr
om C
ente
r
Distance along Tube
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Pollution Reduction
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• Light was used to focus algae in a flow
• A model was created that successfully explained the focusing
• This technique can be applied to detecting pollution
Conclusions
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Xabel Garcia, Salima Rafaı, and Philippe Peyla, Light Control of Phototactic Microswimmer Suspensions Phys Rev Letters 110:138106(1-5), 2013.
Acknowledgements