Overview
CEN ISO/TR 11811:2012 - Nanotechnologies: Guidance on methods for nano- and microtribology measurements (ISO/TR 11811:2012) provides practical guidance for measuring friction and wear where contact sizes are at the nanoscale and microscale. The report focuses on sliding contacts with lateral dimensions from a few nanometres up to 10 µm and applied normal loads between 50 µN and 100 mN. It describes test principles, suitable apparatus, experiment procedures and the influence of test parameters on results. Note: this Technical Report does not cover scanning probe microscopy (SPM) techniques such as frictional force microscopy or atomic force microscopy (AFM).
Key topics and technical requirements
- Scope and significance - defines when nano- and microtribology testing is relevant (MEMS/NEMS and asperity-scale contributions to macroscale tribology).
- Test systems and probe/sample geometry - guidance on probe shapes, tip rounding effects and repeatability of probe geometry; both probe and sample wear must be considered.
- Sample holding - recommended firm clamping; if adhesives are used, minimize thickness and allow curing to avoid viscoelastic or thermal artefacts.
- Motion generation - requirements for well-defined, reproducible relative motion (reciprocating, unidirectional with lift-off, circular); importance of independent displacement measurement and minimizing ground/thermal/airflow noise.
- Normal force application - methods outlined include dead-weight loading, compliant-element loading with dimensional sensors, and active load control using piezo-actuators; attention to parasitic friction and control-loop filtering.
- Measurement parameters and procedures - selection of test parameters should be based on the intended application; the report emphasizes documenting conditions and understanding parameter effects on friction and wear.
- Surface examination, reproducibility and reporting - surface inspection techniques, repeatability/reproducibility considerations, and recommended test report contents are included.
Practical applications
- Characterizing tribological performance of materials and coatings for MEMS/NEMS, microactuators, microbearings and microswitches.
- Simulating nanoscale asperity contacts to inform macroscale tribological models and material selection.
- Research and development of low-friction coatings, thin films and surface treatments where micro/nanoscale contact mechanics dominate.
Who should use this report
- Tribologists, materials scientists, nanotechnology researchers and engineers working on micro- and nanoscale sliding contacts.
- Test laboratories developing nano- and microtribology test methods or validating tribological behavior of microdevices.
- Standards developers and product designers needing guidance on test-system selection, parameter control and result interpretation.
Related standards
- Prepared by CEN/TC 352 in collaboration with ISO/TC 229 (Nanotechnologies). For complementary information, consult other ISO and CEN documents on nanotechnology testing and SPM methods (see ISO/TC 229 publications).