Bioinspired Soft Microrobots with Precise Magneto-Collective Control for Microvascular Thrombolysis

Area of Science:

• Biomedical Engineering
• Materials Science
• Robotics

Background:

• Soft microrobots require biocompatible interfaces, intelligent functions, and collective locomotion for complex biological environments.
• Magnetotactic bacteria (MTB) exhibit efficient collective motion and precise positioning, serving as inspiration for microrobot design.

Purpose of the Study:

• To develop a biomimetic magnetic microrobot (BMM) inspired by MTB for targeted thrombolysis.
• To achieve speedy motion response and accurate positioning control in microrobots for biomedical applications.

Main Methods:

• Constructed BMMs with aligned iron oxide nanoparticle (MNP) chains within a microgel shell, mimicking MTB magnetosomes.
• Utilized interparticle dipolar interactions under static magnetic fields for linear chain assembly.
• Investigated microrobot speed, positioning accuracy, and locomotion control under rotating magnetic fields.

Main Results:

• Achieved maximum speed of 161.7 µm s^-1 with <4% deviation in positioning under rotating magnetic fields.
• Demonstrated frequency-dependent synchronization of BMMs at 8 Hz, with asynchronization at higher frequencies due to drag torque.
• Confirmed BMMs' capability for magneto-collective drug delivery and release for thrombolysis.

Conclusions:

• The developed BMMs show promise for ultra-minimal invasive thrombolysis through targeted drug delivery.
• Biomimetic design inspired by MTB enhances microrobot performance for biomedical applications.
• Collective control and precise locomotion are key for effective microrobot function in vivo.