Inchiscope: A Modular Triple-Balloon Soft Robotic Endoscope for Navigating the Small Bowel

Access to the small bowel remains challenging due to its length, diameter, and curvature, making conventional push endoscopes insufficient for deep exploration. Improved tools that can travel throughout the small bowel without risking mucosal trauma, maintain stable visualization, and offer fine distal manipulation are needed for diagnosis and targeted treatment of small-bowel diseases. This work presents the Inchiscope, a miniaturized modular self-propelled soft robotic endoscope developed to meet the challenges associated with small-bowel access. The presented configuration combines nine independent actuation units to deliver three anchoring balloons and two parallel bellows actuator (PBA) segments for extension/contraction and steering. The modular approach facilitates a minimized diameter (13 mm) while enabling three operation modes including full-body inchworm-inspired locomotion, independent distal segment control for traversing tight bends, and proximal anchoring for stabilized inspection. Characterization highlights stable anchoring at forces up to 12 N, a PBA elongation ratio of 300% and controlled omnidirectional bending to 110◦. Experiments in rigid and compliant phantoms demonstrate self-propelled locomotion at up to 11.4 mm/s and within tubular environments <25 mm in diameter and with bending radii between 30–45 mm, while the independently actuated distal tip delivered continuous 3-D control for observation and positioning in complex geometries.