Mr. Habich, you are developing a robotic system as part of the HALEy research project. Why is there no such device in medicine already?
Tim-Lukas Habich: The project name HALEy stands for "Hydraulic snake-like robot for endoscopy". It is a project of the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG) that supports basic research and entails our collaboration with the Heidelberg University.
Conventional endoscopes are either fully flexible or fully rigid. Rigid endoscopes maintain high stiffness or rigidness but cannot reach target areas that are hidden or difficult to reach. For example, a gastroscopy requires a physician to look at the inside of the stomach. It would be impossible to accomplish this via your esophagus with a rigid endoscope. That is why the physician uses a flexible endoscope to warrant excellent maneuverability. Except for the actuated tip, it has a purely passive structure. The rigidity at the distal end is too low if you want to manipulate tissue with it and provide the doctor with a stable working platform.
Or let’s move past medicine and look at technical applications. Take a borescope, used to inspect aircraft engines, for example. The instrument allows you to check turbine rotor blades or the compressor section. This is where flexible endoscopes come into play for viewing along curvilinear paths. It’s easy to maneuver them into the difficult-to-reach target area. However, the device is too flexible to be used to do maintenance work on the blades.
And this is where your research wants to bridge the gap?
Habich: The core benefit of snake-like manipulators or robots is that the passive shaft is replaced by many actuated segments. However, you rarely see stiffenable mechanisms – even in research. As part of the HALEy project, we examine the principle of the hyper-redundant robot, which features discrete joints. Instead of a passive structure with an actuated tip, you have a snake robot whose body can be fully controlled. This provides the desired rigidity at the end effector to manipulate tissue or work on machines. Cable-driven continuum robots also show great promise in this setting. Our colleagues study the latter for the aforementioned engine maintenance application.