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

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.