Bioinspired helical microswimmers based on vascular plants.

Area of Science:

• Biomimetics and nanotechnology
• Materials science and engineering
• Microfluidics and robotics

Background:

• Nature provides intricate biological structures that can be repurposed for advanced technological applications.
• Helical microswimmers are crucial for targeted delivery and manipulation in microfluidic environments.
• Existing fabrication methods for microswimmers can be complex and expensive.

Purpose of the Study:

• To develop a cost-effective and scalable method for fabricating magnetically propelled helical microswimmers.
• To utilize plant-derived structures for bioinspired microswimmer design.
• To evaluate the performance and locomotion capabilities of these plant-based microswimmers in biological media.

Main Methods:

• Extraction and selection of spiral xylem vessels from various plant species.
• Mechanical stretching to control helical parameters (diameter, pitch) for precise microswimmer fabrication.
• Sequential deposition of titanium (Ti) and nickel (Ni) layers onto plant vessels.
• Dicing of coated vessels to create functional helical microswimmers.
• Testing propulsion efficiency and speed in aqueous solutions and biological media (e.g., human serum).

Main Results:

• Successful fabrication of plant-based helical microswimmers with controlled geometric features.
• Achieved efficient magnetic propulsion with speeds exceeding 250 μm/s.
• Demonstrated robust locomotion in complex biological media like human serum.
• Investigated the relationship between actuation frequency and swimming velocity.

Conclusions:

• Plant-derived xylem vessels offer a simple, cost-effective, and reproducible source for fabricating high-performance helical microswimmers.
• This bioinspired approach significantly reduces manufacturing costs for large-scale production.
• The developed microswimmers show great potential for applications in biological and medical fields requiring precise micro-scale manipulation and transport.