Microrobots for Precision Diagnosis and Treatment in the Digestive System: A Review of Actuation Mechanisms,...

Because lesions associated with digestive system diseases are often deeply seated, embedded within complex luminal milieus, and protected by substantial local delivery barriers, conventional diagnostic and therapeutic modalities remain constrained in their targeting capability, minimal invasiveness, and precision. Microrobots, leveraging micro-scale motion, active navigation, programmable controllability, and theranostic integration, open a new avenue for the precise diagnosis and treatment of digestive system diseases. Here, we review the major actuation modalities and structural designs of microrobots and discuss recent advances in their use across the gastrointestinal and hepatopancreatobiliary systems, focusing on targeted drug delivery, biospecimen harvesting, lesion detection, and interventional treatment. We further discuss the major obstacles to progress in this field, including robust operation in complex in vivo settings, real-time imaging and closed-loop feedback control, biosafety, degradability, and eventual clinical implementation. With continued advances in high-performance materials, multimodal actuation, intelligent control, and convergence with endoscopic and medical imaging technologies, microrobots are poised to accelerate the transition of digestive disease care toward precision, intelligence, and minimally invasive intervention.