Overview
ISO/TR 11811:2012 - "Nanotechnologies - Guidance on methods for nano- and microtribology measurements" provides practical guidance for evaluating the tribological performance (friction and wear) of sliding contacts at the micro- and nanoscale. The Technical Report covers tests for contacts with lateral dimensions from a few nanometres up to 10 µm and applied normal loads in the range 50 µN to 100 mN. It describes recommended test systems, measurement approaches and the influence of test parameters on results. Note: it does not cover scanning probe microscopy (SPM) methods such as frictional force microscopy or atomic force microscopy (AFM).
Key topics and technical requirements
- Scope and definitions: Terms like wear, frictional force and coefficient of friction are defined (references to ASTM G40 definitions are included).
- Apparatus and materials:
- Typical probe/sample geometries and importance of reproducible probe shape.
- Sample holding methods (mechanical clamping vs adhesives) and their influence on stiffness and test outcome.
- Motion generation options: piezoelectric actuators (limited range), servo/stepper motors, voice coils, and the need for independent displacement measurement.
- Normal-force application: dead-weight, compliant-element loading, open- and closed-loop force control and pre-scan strategies to improve load control.
- Friction measurement techniques using displacement transducers or strain gauges; need to maintain orthogonality of normal and friction force axes.
- Real-time wear measurement challenges and thermal/expansion artefacts.
- Temperature control considerations and thermocouple placement.
- Test procedure and parameters: guidance on motion types (reciprocating, unidirectional with lift-off, circular), resolution and filtering of control signals, and the effects of surface form and roughness.
- Reproducibility and reporting: advice on repeatability limits and recommended content for test reports.
Applications
- Tribological evaluation for MEMS and NEMS devices where micro/nanoscale sliding contacts determine device reliability.
- Research into nanoscale mechanisms that underpin macroscale wear and friction.
- Materials development and screening for coatings, lubricants and surface treatments intended for small-scale contacts.
- Calibration and design of test equipment for nano- and microtribology.
Who should use this standard
- Tribologists, materials scientists and surface engineers
- MEMS/NEMS designers and failure analysts
- Test-lab managers and instrument manufacturers
- Research institutions working on nanotribology or wear mechanisms
Related standards and context
- Prepared by CEN in collaboration with ISO/TC 229 (Nanotechnologies). Definitions reference ASTM G40. While ISO/TR 11811:2012 focuses on test guidance, users should consult other ISO and ASTM standards for complementary macroscale tribology methods and metrology guidance.
Keywords: ISO/TR 11811:2012, nanotribology, microtribology, nano- and microtribology measurements, tribological testing, MEMS NEMS wear, friction measurement.