Fluoroscopic control of a magnetorobotic capsule for precision gastrointestinal sampling and delivery

Summary: Untethered gastrointestinal (GI) devices for targeted diagnostics and interventions are constrained by limited capabilities for precise localization, controlled delivery, and reliable retrieval of liquid or gel-based payloads. Here, we introduce G-Bot, a magnetorobotic capsule that integrates fluoroscopic visibility, dual-regime magnetic actuation, and a low-cost, scalable design. The proposed actuation strategy enables decoupled orientation control and on-demand triggering of payload release or sampling. G-Bot provides sufficient radiographic contrast to support accurate manipulation under standard clinical C-arm. Device performance is evaluated in benchtop GI phantom models using samples spanning a range of viscosities under clinically relevant magnetic conditions, demonstrating image-guided sampling, targeted delivery, and feasibility for longitudinal GI monitoring.