Floatable Syntactic Magnesium Foam as a Marangoni-Induced Propulsion Microboat

Area of Science:

• Materials Science
• Nanotechnology
• Fluid Dynamics

Background:

• Syntactic foams offer tunable properties for various applications.
• Lightweight, high-strength materials are crucial for micro-devices.
• Marangoni effect-driven propulsion is a promising method for microscale locomotion.

Purpose of the Study:

• To fabricate floatable syntactic foams from magnesium powder and expanded perlite.
• To investigate the mechanical properties and machinability of the synthesized foams.
• To demonstrate the application of these foams as Marangoni-induced microswimmers.

Main Methods:

• Classical press and sinter process using magnesium powder (<45 µm) and expanded perlite (0.25 g/cm³).
• Forming specimens under 200 MPa pressure followed by high-vacuum sintering at 640 °C for 1 hour.
• Machining the sintered foams into microboat structures for propulsion experiments.

Main Results:

• Successfully produced floatable syntactic foams with densities as low as 0.9 g/cm³.
• Achieved sufficient mechanical strength for precision machining into microboats.
• Demonstrated spontaneous locomotion of microboats propelled by ethanol, reaching speeds of ~160 mm/s and covering distances >350 mm.

Conclusions:

• Floatable syntactic foams derived from magnesium and perlite are viable for micro-device fabrication.
• The synthesized microboats function effectively as Marangoni-induced microswimmers.
• This study highlights a novel approach for creating self-propelled micro-devices with potential applications in microfluidics and targeted delivery.