Fraunhofer Institute for Mechanics of Materials IWMThe E-Bear 2 project aimed to identify sustainable lubricants for electrically programmable friction. The goal was to reduce friction in plain and roller bearings in a targeted manner by applying electrical potentials. To this end, ionic liquids were used as additives in non-oil-based lubricants to minimize the CO₂ footprint. Targeted control of surface chemistry not only optimized the coefficient of friction under different operating conditions but also minimized wear.
Development of sustainable bearing systems with minimal friction and wear losses through electrically programmable friction
Completed research project
Project description
The E-Bear 2 project focused on transferring the technology of electrically programmable friction to sustainable lubricants for plain and roller bearings. Based on initial successes with ionic liquids (ILs) and their mixtures, the reduction in friction coefficient in a tribological model system was demonstrated by applying electrical potentials.
Water- and polyalkylene glycol-based (PAG) lubricants were investigated, each equipped with special additives to improve sliding behavior under changing operating conditions. The aim was to optimize friction and wear under varying temperature and load by controlling electrical potentials. In addition, the project explored whether the tribological state of superlubrication (coefficient of friction < 0.01) could be stabilized or induced using electrical potentials.
Challenges included adapting the tribological test rig and defining suitable potential protocols for friction control. Collaborations with industry partners and university clusters of excellence supported the development of industrially viable, sustainably certified lubricants.
Transfer of project results to the following Fraunhofer IWM R&D services for companies:
- Reduction of friction in plain and roller bearings through electrically programmable lubricants
- Focus: Sustainable lubricants (water- and PAG-based), friction coefficient control, superlubrication
- Challenges: Adaptation of the tribological system, development of chemically stable mixtures
- Future steps: Verification of friction coefficient reduction with water and PAG-based lubricants, production of a demonstrator
