Combining tethered and untethered magnetic robots via a magnetically triggerable latch for target payload delivery and retrieval.

The reach and scope of minimally invasive surgical procedures can be transformed via the development of continuum robots. Through soft, flexible structures and accurate navigation, previously inaccessible anatomical regions can be safely reached. Dependent on both actuation mode and clinical application, however, rigidity and miniaturization potential can still present substantial challenges. Magnetic soft continuum robots (mSCRs) offer promising solutions to these key questions. Furthermore, micrometer- to millimeter-scale untethered magnetic robots (mUMRs) offer unparalleled miniaturization potential enabling targeted therapeutic delivery. Leveraging the benefits of magnetic actuation, this study introduces a bespoke, continuously magnetized catheter that synergizes the navigational strengths of mSCRs with the functional effectiveness of mUMRs to precisely deliver drug-doped payloads to otherwise unreachable regions deep within the anatomy. In particular, this system uses a magnetic latching mechanism, ensuring precise drug delivery and efficient retrieval, demonstrated in an ex vivo porcine kidney model for organ transplantation-related immunosuppressant delivery.