Professor Jee-Hwan Ryu's research team has developed a new soft growing robot technology that enables the formation of a stable inner channel, allowing for the integration and delivery of tools during growth. This advancement allows the robot to navigate freely and operate effectively in confined and complex environments, paving the way for innovative applications in disaster response and medical intervention.

What if a robot could enter narrow, complex spaces to assist with rescue operations or perform medical tasks deep inside the human body? Soft growing robots capable of making body extensions akin to a growing plant have been developed to take on such roles. Unlike conventional robots made of rigid materials, these robots are constructed from thin and flexible membranes, allowing them to navigate challenging environments while remaining stable. However, a key limitation remains: it is difficult to maintain a stable inner channel through which tools can be delivered or used.

Professor Jee-Hwan Ryu’s team has proposed an innovative solution to this challenge. The core idea is to use an inflatable structure that can expand with air pressure to maintain a consistent and stable passage inside the robot. The robot contains several small internal tubes, known as sub-vines, which inflate during growth and play a key role in maintaining the inner channel, as shown in Figure 1.

The effectiveness of this method was verified through a series of experiments. By inserting pipes of various diameters into the robot’s inner channel and pulling them across a set distance, the researchers confirmed that smaller tools could move stably through the channel. Even as the robot extended its length, the inner channel remained stable, and its ability to steer was also successfully demonstrated, as shown in Movie 1.

This technology is highly applicable in areas such as rescue missions, medical procedures, and industrial inspections. For instance, the robot could enter a collapsed building and send sensor-equipped tools through its channel to survey internal conditions, or it could be adapted as a next-generation endoscopic system capable of switching tools during minimally invasive surgeries. This capability is effectively demonstrated in Movie 2.

By replacing bulky mechanical systems with a flexible robot that preserves a stable inner passage, this research presents a significant advancement for robots operating in constrained and complex spaces. It offers a new direction for soft robotics, expanding the roles these systems can play across a wide range of practical environments.

This research, with Ph.D. candidate Dongoh Seo participating as the first author, was published in IEEE Robotics and Automation Letters, Vol. 9, No. 9 (September 2024), and received the RA-L Best Paper Award. (Title: Inflatable-Structure-Based Working-Channel Securing Mechanism for Soft Growing Robots. Link: https://ieeexplore.ieee.org/document/10592830)