Breaking through Barriers: Ultrafast Microbullet Based on Cavitation Bubble.

Area of Science:

• Materials Science
• Nanotechnology
• Fluid Dynamics

Background:

• Micromotors offer potential in biomedical and reservoir exploration but are limited by insufficient propulsion.
• Overcoming biological barriers and reservoir boundaries requires advanced micromotor capabilities.

Purpose of the Study:

• To develop an ultrafast microbullet utilizing laser cavitation for enhanced propulsion.
• To investigate the motion mechanism and influencing factors of the microbullet under laser action.

Main Methods:

• Experiments conducted using high-speed photography.
• Boundary integral method employed to analyze microbullet motion.
• Systematic exploration of laser intensity, microbullet size, and temperature effects.

Main Results:

• Achieved instantaneous velocities up to 5.23 m/s for polystyrene (PS)/magnetic nanoparticle (MNP) microbullets.
• Demonstrated strong penetration ability and targeted motion driven by laser cavitation.
• Identified key factors influencing microbullet dynamics.

Conclusions:

• Laser cavitation provides an effective propulsion mechanism for microbullets.
• The developed microbullet technology enhances micromotor capabilities for challenging applications.
• This propulsion strategy opens new avenues for micromotors in engineering and beyond.