Melt Electrospinning Writing of Magnetic Microrobots.

The magnetic microrobots actuated by an external magnetic field can access distant, enclosed, and small spaces under fuel-free conditions, which is apromising technology for manipulation and delivery under microenvironment; however, the complicated fabrication method limits their applications. Herein, three techniques including melt electrospinning writing (MEW), micromolding, and skiving process are combined to successfully mass-produce tadpole-like magnetic polycaprolactone/Fe3O4 (PCL/Fe3O4) microrobot. Importantly, the tadpole-like microrobots under an external magnetic field can achieve two locomotions: rolling mode and propulsion mode. The rolling motion can approach the working destination quickly with a speed of ≈2 mm s-1. The propulsion motion (0-340 µm s-1) can handle a microcargo. Such a simple and cost-effective production method shows a great potential for scale-up fabrication of advanced shape-design, mass-production, and multifunctionality microrobot.