A Self-Powered Bimodal Tactile Sensing Cap for Colonoscopic Examination

The distal end of a colonoscope typically lacks tactile sensing capability, posing risks of intestinal injury during examination. This study proposes a self-powered hydrogel-based tactile sensing cap (TSC) for contact force and tissue stiffness perception in colonoscopy. The TSC employs a biocompatible hydrogel as a flexible sensing interface, where the Gelatin PVA hydrogel offers excellent flexibility, tunable adhesion, and positive triboelectricity, generating significant electrical signals during contact-separation with the colon wall. The interfacial viscous effect between the Gelatin PVA hydrogel and lesioned tissue induces characteristic signal waveform changes, reflecting tissue stiffness variations and enabling accurate assessment of lesion hardness. This self-powered, structurally simplified bimodal TSC enhances procedural safety and diagnostic precision through a simple design, laying the foundation for next-generation smart colonoscopy systems while supporting early lesion screening.