Geometry-Controlled, Magnetically Guided Light-Driven Micromotors via Capillary-Assisted Particle Assembly

Area of Science:

• Materials Science and Engineering
• Microfluidics and Nanotechnology
• Chemical Engineering

Background:

• Micromotor performance is highly dependent on their geometry and surface properties.
• Existing fabrication methods struggle with scalable, controlled shapes and integrated functionalities.

Purpose of the Study:

• To present a modular platform for fabricating shape- and size-controlled, light-activated micromotors.
• To enable deterministic geometric design combined with multifunctional surface integration.

Main Methods:

• Utilized Capillary-Assisted Particle Assembly (CAPA) with silica microparticles.
• Assembled particles into predefined geometries using meniscus-driven capillary trapping in patterned templates.
• Applied thin-film deposition (titanium, nickel, titania) for structural, magnetic, and photocatalytic properties.

Main Results:

• Successfully fabricated linear, L-shaped, and tripod-shaped micromotors.
• Demonstrated active propulsion (~3-5 µm s⁻¹) under UV light in hydrogen peroxide.
• Achieved guided movement, selective cargo capture, transport, and release for in-plane manipulation.

Conclusions:

• The CAPA platform offers a simple, versatile method for fabricating customized micromotors.
• This approach integrates deterministic geometry control with multifunctional coatings.
• The developed micromotors show potential for applications in microfluidics, lab-on-a-chip, and active-matter systems.