ERC Consolidator Grant for soft robotics researcher

Whether artificial hands with an especially gentle touch or an endoscope that crawls through the intestines like a worm, robots made of soft materials could soon carry out tasks that are difficult for metal-based systems. Dr. Philipp Rothemund, assistant professor at the University of Stuttgart, seeks to simplify how soft robots are controlled. The European Research Council (ERC) is funding the project with one of its prestigious Consolidator Grants worth up to €2 million.

“I would like to congratulate Philipp Rothemund on this award. Soft robotics is a growing field of research with relevance across many areas of society, and Philipp Rothemund is already an internationally recognized pioneer in this field. Together with his team, he is laying the essential scientific foundations to prepare this new generation of robotic systems for their future practical application,” says Prof. Manfred Bischoff, Vice Rector for Research and Sustainable Development at the University of Stuttgart. 

Benefits for many areas of application

Robots made of soft, flexible materials offer various advantages. Because they can be deformed, these robots can reach otherwise inaccessible spaces and, in the event of a natural disaster, be used to search for survivors. Because they lack a rigid skeleton, the risk of damage or injury is also reduced. Among other things, they could assist nursing staff in repositioning patients.

“Despite this potential, the field of soft robotics is still waiting for its big breakthrough,” says Philipp Rothemund, assistant professor at the Institute for Adaptive Mechanical Systems (IAMS) at the University of Stuttgart. “One reason is that complex control technologies are usually required to allow robots to move in a controlled manner,” he explains. Soft fluidic robots, for example, consist of numerous chambers filled with air or water by pumps and valves. By appropriately adjusting the pressure in each chamber, it is possible to make the fingers of a mechanical hand bend.

Innovative approach expected to drive a breakthrough

In his ERC project Phase Transitions for the Generation and Control of Complex Motion in Soft Robots (PHASEBOT), Rothemund aims to fundamentally simplify the motion control of soft robots. To achieve this goal, he will harness the physical effects that occur at phase transitions. Scientists understand phase transitions as the phenomenon in which some materials suddenly change their state. For example, distilled water begins to boil at 100°C.

At first, the boiling temperature must be exceeded by a few degrees before the water begins to vaporize. To overcome this boiling delay, a little more energy is needed for a short time. “This behavior is typical for phase transitions,” says Rothemund. When a chamber of a fluidic robot is inflated like a balloon, this process too can be considered a phase transition. Here, too, a great deal of pressure is required at the beginning before the first bulge forms. Once this threshold is crossed, the process suddenly becomes easier.

Researchers aim to harness the behavior observed at phase transitions

This phenomenon allows specific areas of a soft robot to be deformed by designing the pressure thresholds at which the phase transition occurs. The other parts remain in their original condition.

“We also want to be able to vary the part we deform – simply by transferring electrical charge to the skin of the robot via electrodes,” explains Rothemund. This is because electrostatic charging can locally weaken the initial pressure. When pressure is applied to the electrically charged robot, the bulge forms in a different location than it normally would. In this way, a robotic worm could be made to thicken and thin again in a wave-like motion along its body – much like a crawling earthworm. Because it would not need to consist of several chambers that are addressed separately, a large part of the complex control technology would no longer be necessary.

Basis for a new generation of soft high-performance robots

The aim of the ERC project is to precisely control the transition of flexible materials into a “deformed phase” and apply it for motion control. Over the next five years, the participants will not only develop suitable materials for this purpose but also construct a model robot arm that can move in three spatial directions and grasp objects at the appropriate position. “We are working on a new paradigm for motion control that will serve as the basis for the development of a new generation of soft, high-performance robots,” says Rothemund.

About Assistant Professor Philipp Rothemund
Philipp Rothemund has been a Tenure Track Professor for Functional Soft Robotic Matter at the Institute for Adaptive Mechanical Systems (IAMS) at the University of Stuttgart and a visiting scientist at the Max Planck Institute for Intelligent Systems (MPI-IS) since 2023. He was elected spokesperson of the Young Academy in 2025 and was recently selected for the “Top 40 Under 40” list of Capital business magazine, which annually recognizes outstanding young individuals shaping the future of Germany. Rothemund’s academic career has taken him to Harvard University in Cambridge, Massachusetts, and to the University of Colorado in Boulder. He earned his PhD in engineering in 2018.

About the ERC grants
ERC grants from the European Research Council are considered a hallmark of the international competitiveness of a university. They are divided into five funding lines: Starting Grants, Consolidator Grants, Advanced Grants, Synergy Grants, and Proof of Concept. Consolidator Grants are intended as a funding instrument for outstanding scientists whose research group is in the consolidation phase. In this funding round, 349 cutting-edge researchers carrying out their projects in 25 EU member states and associated countries were awarded with a Consolidator Grant.

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