Run-and-tumble dynamics of active giant vesicles.

Area of Science:

• Soft Matter Physics
• Biophysics
• Materials Science

Background:

• Cell-inspired designs are crucial for developing self-regulating artificial microswimmers.
• Lipid vesicles offer a versatile platform for creating functional microscale systems.

Purpose of the Study:

• To fabricate Janus lipid vesicles with reconfigurable motion using membrane fluidity.
• To investigate the self-propulsion and dynamic behavior of these vesicles under external electric fields.

Main Methods:

• Fabrication of giant unilamellar vesicles (GUVs) with temperature-dependent phase separation.
• Utilizing 2D domain analysis to characterize membrane states.
• Applying external electric fields to induce and observe vesicle motion.

Main Results:

• Janus lipid vesicles self-propel under electric fields, mimicking colloidal behavior.
• Membrane fluidity coupled with electric fields induces transitions between phase-separated and disordered states.
• These transitions result in distinct run-and-tumble dynamics, with tumbles caused by loss of Janus asymmetry.

Conclusions:

• The cell-inspired Janus vesicles exhibit reconfigurable, dynamic motion driven by electric fields.
• The observed run-and-tumble behavior is linked to membrane phase transitions and loss of asymmetry.
• This system presents a novel strategy for creating programmable, motile artificial cells.