Abstract
Vine robots are soft robots that translate by everting, or growing, from their tips. This mechanism of translation minimizes the application of shear forces on the environment, making them particularly well-suited for surgical tasks, such as colonoscopy. However, steering and retracting vine robots within tortuous and delicate environments presents significant challenges. In this paper, we introduce a novel soft robotic system for colonoscopy that consists of an inchworm-inspired device -the InchIGRAB -nested within a vine robot. The InchIGRAB is designed to enable steering of the vine robot along curved paths, as well as to enable controlled retraction of the vine robot after it reaches its target. We present the design, modeling, and fabrication of the robotic system and characterize its performance. Furthermore, we demonstrate the presented robotic system's ability to safely navigate the entire colon length, including several curved sections, during both forward motion and retraction, highlighting its potential as a robotic colonoscope that offers enhanced safety for patients.