Medical instruments such as endoscopes, catheters, and industrial inspection tools are long and thin instruments which typically deploy by translation of their body relative to their environment. This mode of locomotion poses some sets of limitations. Indeed, friction with the environment can cause these tools to damage their environment. This is the case for medical applications such as colonoscopy, for instance, where the pushing action involved in advancing a colonoscope can induce large mechanical stresses on the delicate tissues and cause bleeding. In addition, such instruments may fail to deploy in industrial contexts such as the inspection of a pipe network, due to added friction in successive turns. To solve this challenge, inflatable, bio-inspired robots called “vine” robots have been proposed in the literature.

Vine robots are inflatable, bio-inspired robots which grow at the tip to deploy. To have such characteristics, vine robots are composed by a thin tube everted in itself at the tip. When pressurized, the material stored inside, called the vine robot tail, translates and reaches the tip where it everts. The material everted at the tip then forms the vine robot body, which remains stationary with respect to the environment. These robots have been advantageously proposed for medical applications such as the deployment in the vasculature, in the mammary duct, in the intestine, and for industrial and larger scale applications such as growth in granular environments, inspection of archaeological sites, and for search and rescue operations. Most applications require a passageway for tools, i.e. a working channel, in order to provide direct access to the robot tip from the base. This enables tools to be inserted and swapped, in order to perform some tasks. Tasks can include the use of cameras and light sources for site visualization, laser, grippers and cutting tools in surgical applications, or the transmission of water or goods for search and rescue applications. Recently, several research have tackled the inclusion of such working channels in vine growing robots, including recent work of the PI, which enables working channels in miniaturized vine robots, thanks to material scrunching.

However, while previous work focused on the deployment of these robots, it was shown in the literature that their retraction remains a significant unsolved challenge. This issue prevents their practical use, as well as their adoption by the industry, and thus presents a major challenge for the adoption of these robots. In particular, while vine robots with working channels seem the most useful from an application perspective, only the retraction of vine robots without working channels has been explored to date. Therefore, the goal of this thesis will be to propose general multi-scale solutions for the retraction of vine growing robots with working channels. Applications in the medical and industrial fields will be proposed to show the benefits of the investigated solutions, in challenging contexts.