Researchers aim to develop new supermaterial for robots

By Sebastian Wittrock, sewitt@tek.sdu.dk, 4/24/2024

Most of us know that materials have different grips on various types of surfaces. If you're playing football on a wet pitch, it's a good idea to have studs on your soles. And equally, if you want to run fast on asphalt, smoother shoes are probably better.

But imagine if the same shoe sole could change shape and structure and be used on all types of surfaces.

The scenario might not be as far-fetched as one might think. At SDU Biorobotics, researchers are working as part of the European doctoral network MAESTRI to develop a soft material that can change its surface and, thereby, friction through magnetism.

Initially, however, it won’t be used for ordinary shoe soles but for robots, explains professor Poramate Manoonpong:

- Picture a robot whose feet are covered with a soft material like rubber or silicone. In certain situations, the robot moves with a certain friction from the material to the surface, but if it encounters a new environment that requires more grip or friction, and the material remains unchanged, it might lose its grip, the professor says.

- A solution to this could be to deform the material to create a certain roughness on the surface, so the robot could potentially achieve better grip.

It is Poramate Manoonpong, who, along with associate professor Xiaofeng Xiong and a PhD student, will be responsible for the project at the University of Southern Denmark over the next four years. The SDU team will specifically focus on developing adaptive control methods for magnetoactive soft materials in robotic applications.

The ambition is for the material to function as a kind of supermaterial that will enable robots to move much better and potentially make the locomotion control systems simpler. It could also be used on the grippers of industrial robots, for example, to grasp slippery objects or foods that would be damaged by ordinary grippers.

The potential is enormous, and that is also why researchers all over the world are looking towards this field. But it's not an easy task, says the professor:

- The idea is to mix ferromagnetic particles, iron for instance, into the soft material and then expose the material to a magnetic field to deform it. But the major challenges lie in how these particles should be embedded in the material, the composition of the mixture, the choice of material, the optimal surface structure or pattern for the material, and control of the material by a magnetic field.

Another challenge  is that all of this might work in a lab, but as soon as you put the material on the feet of a real robot that maybe weighs 3-4 kilograms, would  a magnetic field  be able to maintain the texture on the surface of the soft material?

To solve these challenges, one has to think interdisciplinarily, and that's the whole point of the project, says Poramate Manoonpong:

- MAESTRI is an interdisciplinary network funded by the EU's Marie Sklodowska-Curie Actions, where the aim is precisely to educate new PhDs with cross-disciplinary competencies, not just in robotics but also in material science, chemistry, physics, and biology.