Catheter‐Deployable Janus Hydrogel Actuator for Magnetically Guided Biliary Repair With Machine‐Learning Assisted Mechano‐Sensing

ABSTRACT Endoscopic sphincterotomy (EST) remains essential for managing biliary obstruction but lacks tools that both restore tissue integrity and continuously monitor sphincter mechanics post‐procedure. This work introduces a catheter‐deployable, magnetically guided Janus hydrogel actuator patch that couples precise biliary sealing with real‐time mechano‐sensing. The bilayer design integrates a hydrophobic PDMS/Fe 3 O 4 top layer for magnetic steering and anti‐adhesion with a hydrophilic PNIPAM bottom layer that swells to conform and adhere to mucosa, enabling secure deployment and anti‐reflux sealing. Mechanical deformations are transduced into resistance changes with fast electrical response (≈79 ms) and recovery (≈85 ms), supporting continuous readout of contraction, dilation and subtle vibrations. In benchtop ducts and ex vivo intestinal models, the patch exhibits directed motion under uniform fields, stable adhesion under sustained flushing and agitation, and repeatable thermo‐/swelling‐driven actuation. Waveform features of relative resistance enable machine‐learning classifiers to discriminate multiple deformation states with high accuracy, providing objective indicators of healing progression. This soft, steerable hydrogel platform addresses an unmet need in post‐EST care by unifying minimally invasive deployment, robust sealing and quantitative biomechanical monitoring, and it offers a generalizable route to personalized management of biliary and other soft‐tissue repairs.