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