Development of a leech-inspired peristaltic crawling soft robot for intestine inspection

The development of a non-destructive and patient-friendly method for examining the intestines is crucial for early prevention and timely diagnosis of prevalent intestinal diseases that pose a threat to human health worldwide. Although the soft robot shows promise as an examination method due to its safe human-machine interaction and high maneuverability, achieving controlled and non-damaging movements within the flexible and delicate structure of the intestines remains a significant challenge. In this study, we propose and design a leech-inspired soft robot capable of operating in an intestine-like environment while ensuring lossless and controllable functionality. The soft robot consists of two dual-chambered adsorption actuators serving as "feet" and a retractable actuator as the body, enabling the robot to crawl by programmatically controlling the alternating movements of the adsorption actuators and the cooperation of the retractable actuator. Through numerical simulations, and movement tests in various scenarios such as planes, slopes, and intestine-like pipelines, we verified the adsorption characteristics and regulation mechanism of the adsorption actuator, as well as the movement performance of the robot. The results demonstrate that the adsorption actuator achieves a maximum adsorption force of 3.17 N, and the soft robot attains a maximum moving speed of 9.29 mm/s. This research offers a non-destructive and patient-friendly approach that holds promise for the detection and treatment of intestinal diseases in practical applications.