Comparison of Theoretical and Measured Forces on Magnetically Propelled Microrobots in a Vascular Phantom

Microrobots can travel in blood flow to targets that are currently difficult to reach. Stationary control is a prerequisite and requires the prediction of major influencing forces. During experiments, a magnetic cylindrical microrobot was moved in a tube filled with water or a glucose mixture (blood analog), controlled by an external electromagnetic field. The experimental results showed that the magnetic field gradient needed to be increased at the highest rate for smaller microrobots in the glucose mixture. At low fluid flow velocities, a magnetic gradient field of approximately 130–200 mT/m was required to overcome the static friction force, which was significantly higher than the drag force.