Doctoral Programs student Ayato Kanada came up with his leech-like robot in a place you’d least expect it: His bathroom.

“The shower hose went wild, as if it had come alive, when I inadvertently turned on the faucet at maximum,” Kanada told Tech Briefs.

The shower-hose-with-a-life-of-its-own gave the researcher an idea:

“If I could manipulate a hose, I might be able to make a robot with the dynamic movement of a living creature,” said Kanada, who studies at Japan’s Toyohashi University of Technology.

Along with Toyohashi University mechanical engineering professor Dr. Tomoaki Mashimo and University of Cambridge robotics engineer Dr. Fumiya Iida, Kanada did just that, and developed a leech-shaped robot.

The Longitudinally Extensible Continuum-robot, or “LEeCH,” can climb vertical walls, thanks to its flexible body.

Made with shower-hose material and two suction cups, the robot elongates and bends without constraints — just like a leech.

The robot has successfully suction-cupped its way over a vertical wall.

In an interview with Tech Briefs,Kanada explains where the leech robot is likely to go next.

Tech Briefs:Why is it advantageous for a robot to be designed like a leech? What is a leech-like robot able to do?

Ayato Kanada: Leeches are known as excellent climbers, propelling themselves using soft extensible bodies and two suckers attached at both ends. We imitated their two features.

One is their soft and lightweight bodies. With this feature, they aren't in any grave danger, even if they fall from height. The other is the extensible mechanism of their bodies. They can move through complex terrains and achieve some transitions efficiently by elongating their bodies greatly.

Our robot with these two features can climb up and over a wall, and then move to the other side of the wall to climb down again. This is the world’s first achievement in developing a soft and flexible robot that is capable of the wall-to-wall transition.

Tech Briefs:What are the essential components of the technology that allow the robot to have leech-like capabilities?

Kanada:To mimic the advantageous properties of leeches — namely, being lightweight, flexible, and extensible — we propose a new mechanism using the tube structure of the shower hose.

The flexible tube, with a metal plate and an S-shaped, spirally wound profile, has been used in general households. A gear engages with the helical groove on the surface of the tube. The flexible tube moves back and forth by the rotational motion. The robot has a body composed of three flexible tubes that are connected in parallel. The body can bend or elongate by controlling the length of each flexible tube fed by the gear.

Tech Briefs:What kinds of applications do you envision for this kind of robot?

Kanada:Climbing robots have a wide range of potential applications, including building inspection, maintenance, construction, and search-and-rescue tasks. For more interesting applications, it is desirable to apply to inspections and cleaning of ships, planes, and space stations that have structures with more complicated curved surfaces and steps.

Tech Briefs:How did you test the robot?

Kanada:To understand the potential of our robot, some types of locomotion were tested on a vertical plastic wall. Our robot has succeeded to climb up, down, and sidewalk a wall; climbed up a wall and transitioned to a flat surface; and climbed up and over a wall.

Tech Briefs:What’s next regarding this work?

Kanada:Making the most of the hollow structure of the shower hose, we are considering the possibility of changing the stiffness of the tube by pouring fluid into the cavity. A robot with flexible body structure is not only highly adaptable to environment, but also highly secure against collision. It has a potential application to also reduce the impact to a human’s body during labor.

What do you think? Will a leech robot help with tasks like search-and rescue? Share your comments and questions below.

The University of Toyohashi study can be found in the April 2019 scientific journal Soft Robotics.