Light Control of Localized Photobioconvection

Area of Science:

• Biophysics
• Microbiology
• Fluid Dynamics

Background:

• Microorganismal motility involves complex responses to environmental stimuli.
• Controlling active matter motion offers novel applications in various fields.

Purpose of the Study:

• To leverage the phototactic ability of Chlamydomonas reinhardtii for controlled manipulation of microalgal suspensions.
• To develop a novel method for controlling bioconvection using light stimuli.

Main Methods:

• Utilized the phototactic response of Chlamydomonas reinhardtii.
• Applied localized photoaccumulation to induce cell clustering.
• Developed a continuum model to describe phototactic responses and bioconvection dynamics.

Main Results:

• Achieved precise, real-time control over the timing and position of cell photoaccumulation.
• Demonstrated the controlled development of isolated bioconvective plumes.
• Showcased the ability to activate and stop bioconvection in real time using light fields.

Conclusions:

• Photobioconvection provides a novel, efficient method for mixing biological suspensions.
• Light fields can act as an external switch to control spatiotemporal dynamics of bioconvection.
• This approach offers precise and reconfigurable control over active matter at both individual and collective levels.