Gear-Train-Enabled Ingestible Capsule System Toward Wireless Targeted Intestinal Biopsy

Abstract

Diagnosing gastrointestinal (GI) diseases affecting the small intestine is a prevalent healthcare challenge as traditional procedures require sedation and have limited small intestinal access. Ingestible capsule technologies have emerged as a promising minimally-invasive alternative to endoscopic procedures, offering access to the entire GI tract. However, biopsy capsules have yet to translate clinically due to their external stimulation or power requirements. Here, an ingestible low-power thermomechanical gear-train actuation system featuring a hybrid 3D-printed tissue scraper is demonstrated. The system easily interfaces with ingestible capsule-based electronics for on-command activation with a power requirement of 150-180 mW, a ~40-80% power reduction compared to previously demonstrated prototypes. The tissue scraper features a $1~\mu $ m blade requiring $0.208\pm 0.053$ N to penetrate phantom tumor tissue to a $500~\mu $ m depth. An average output force of $2.5\pm 0.8$ N was demonstrated by the system, surpassing the necessary penetration force. Testing on ex vivo tissue showed a collection volume of $1.5\pm 1.2$ mm³ which is relevant for histological and genetic analysis. The device was integrated with ingestible electronics which wirelessly initiate activation; a necessary capability for future feedback-driven sampling. Overall, the biopsy system represents an advance toward autonomous small intestinal tissue biopsy, introducing a new paradigm for GI disease diagnosis. [2026-0013]