Multifunctional 3D-Printed Pollen Grain-Inspired Hydrogel Microrobots for On-Demand Anchoring and Cargo Delivery

Area of Science:

• Biomedical Engineering
• Materials Science
• Robotics

Background:

• Existing wireless microrobots have limited functional diversity due to stimulus input range and coupled responsive functions.
• This coupling leads to overlapping task operations, hindering complex biomedical applications.

Purpose of the Study:

• To develop a 3D-printed, multifunctional microrobot inspired by pollen grains.
• To overcome limitations of current microrobots by enabling independent control over diverse functions.

Main Methods:

• Fabrication of microrobots using 3D printing with three distinct hydrogel components: iron platinum (FePt) nanoparticle-embedded pentaerythritol triacrylate (PETA), poly N-isopropylacrylamide (pNIPAM), and poly N-isopropylacrylamide acrylic acid (pNIPAM-AAc).
• Integration of specific functionalities: magnetic field response for locomotion, temperature response for anchoring, and pH response for cargo release.

Main Results:

• Demonstrated independent control over microrobot steering (magnetic fields), surface attachment (temperature), and cargo release (pH).
• The pollen-inspired design allows for torque-driven surface rolling and precise steering.
• On-demand surface attachment and targeted cargo release were achieved through responsive hydrogel components.

Conclusions:

• The developed microrobots exhibit versatile, multi-responsive capabilities for complex biomedical functions.
• This novel design enhances microrobot performance and functional diversity, paving the way for future medical applications.
• Independent control over distinct functions represents a significant advancement in microrobot technology.