Automated Fabrication of 3D Printed Magnetic Soft Robots With Programmable 3D Magnetizations

Magnetic soft robots (MSRs) are a viable tool for many biomedical applications, such as targeted drug delivery and minimally invasive surgery, since they can be actuated remotely using external magnetic fields. These robots are developed by programming ferromagnetic domains with specific magnetizations using magnetic particles embedded in a flexible substrate. Existing fabrication methods rely on partially automated or manual processes, which limit production rates and realistic design iterations. To address these challenges, a fully automated workflow that translates robot simulations into an instruction set for a stereolithography 3D printer is presented. In this process, a rotating permanent magnet is used to program 3D magnetizations by reorienting hard magnetic particles within a photosensitive resin. Geometric resolutions of 1.6 mm are achieved with a layer height of 0.1 mm, enabling the creation of structures 14 layers thick. Beam bending tests identify an optimal 6:1 resin‐to‐magnetic particle mass ratio, yielding a maximum deflection angle of 80°. Demonstrated applications include rolling and climbing locomotion in a maze and independent control of each arm in a multiarmed robot. By enabling fast, repeatable production of MSRs within 30 min, this automated system shortens the feedback loop from design to application, advancing their potential as a biomedical tool.