A magnetically actuated robotic capsule endoscope for in-situ visualization and microneedle-mediated targeted drug delivery in gastrointestinal tract

Capsule endoscopy has revolutionized gastrointestinal (GI) diagnosis but is limited to imaging, often requiring invasive procedures for subsequent therapy. This work presents a magnetically actuated robotic capsule endoscope (MARCE) that integrates controllable magnetic navigation, real-time visualization, and targeted drug delivery via microneedle patches to bridge the gap between diagnosis and therapy. The MARCE features a retractable micro-camera for continuous monitoring of the GI tract, dual-layer hyaluronic acid microneedle patches enabling multi-point drug administration, and an electrothermally triggered protective cover to prevent premature dissolution in GI fluids. Sized similarly to conventional clinical capsules (11.8 mm in diameter and 21.5 mm in length), the MARCE demonstrates controlled epinephrine release from its microneedle patches (up to 0.4 mg) and provides sufficient magnetic actuation force (~0.58 N) and torque (~18.4 N mm) for intestine locomotion and penetration. Driven by a custom-developed electromagnetic actuation system, the MARCE achieves precise 3D locomotion with an average positional error <1.5 mm controlled microneedles penetration (with a peak force of 0.15 N), and successful drug delivery across multiple lesions in ex-vivo porcine intestinal tissue. This integrated platform streamlines diagnostic-therapeutic workflows, offering a minimally invasive solution for GI disorders such as bleeding, with potential to enhance patient comfort and treatment precision.