Automated Actuation of Biodegradable and Self-Fluorescent Chlorella Swarms Using Magnetic Tweezers

Area of Science:

• Biomedical Engineering
• Materials Science
• Robotics

Background:

• Automated assembly and actuation of functional large-volume microrobot swarms remain challenging for targeted therapy.
• Chlorella algae offer unique properties like self-fluorescence and biodegradability, making them suitable templates for microrobot development.

Purpose of the Study:

• To prepare magnetic Chlorella-based microrobots (MCS) and demonstrate their assembly, actuation, and navigation capabilities for potential therapeutic applications.
• To utilize Chlorella's natural properties for creating functional, biodegradable microrobots.

Main Methods:

• Magnetic microrobots were fabricated using Chlorella as a template via magnetron sputtering.
• A magnetic tweezer system with a robust magnetic field was employed for the assembly and actuation of large-volume Chlorella swarms.
• The mobility and navigation of the MCS were evaluated in various simulated environments, including spiral and crossed channels, and in vitro on articular cartilage fragments.

Main Results:

• The developed magnetic Chlorella swarms (MCS) exhibited excellent degradation capability and mobility.
• Successful automatic navigation was demonstrated in diverse scenarios, including a spiral channel with bovine serum and a simulated channel.
• In vitro studies confirmed the motion capacity of MCS on real articular cartilage fragments.

Conclusions:

• This research presents a novel functional microrobot swarm platform based on biodegradable Chlorella.
• The developed MCS demonstrate controlled movement and navigation, paving the way for targeted drug delivery and precision therapy applications.
• The study highlights the potential of bio-inspired microrobots for advanced medical interventions.