Fabrication and Testing of Bioinspired Surface Designs for Friction Reduction at the Piston Ring and Liner Interface

Abstract The piston ring and liner interface is a major source of friction loss in automotive combustion engines. This loss can be mitigated by learning from surfaces from nature that manipulate friction. In this study, novel fabrication and testing methods were developed and used to efficiently compare three-dimensional bioinspired surface designs to existing piston liner surface topographies. Surface designs inspired by frog toes were fabricated using two-photon lithography, and their frictional performance is compared to that of typical piston liner topography. These designs reduce surface friction by an average of 18%, and up to 39%, compared to a flat control. The developed fabrication and testing methods allow comparison with existing topographies without needing to transfer the designs to the original materials and provide an efficient approach for designing surfaces to meet the frictional challenges of the future.