A central aspect of micro tribology is the measurement of friction by characterising the force between two interacting surfaces in relative motion. Since the applied force not only induces friction, but also wear, it is important, in the case of many soft materials (e.g. polymers, gels or biological tissues), to have a non-destructive friction-measuring technique. For such applications in micro tribology, the micro-tribometer is the optimal technique, since very small forces can be used and large samples can be measured. SuSoS focuses on the tribological analysis of soft materials, such as contact lenses, cartilage, skin, blood vessels, and so on.

The micro-tribometer relies upon the perpendicular deflection of a two-legged cantilever to set the normal force and simultaneously determine the friction force. By using optical fibers, differences in the reflection of a laser beam on two small mirrors are detected. Changes in the distance between the fiber and mirror are multiplied by the spring constant and converted into force. The coefficient of friction is obtained from the ratio of friction force and normal force.

Benefits of this analyzing technique

  • Minimal forces (comparable with AFM) applied on macroscopic samples make the analysis of biological systems and very thin layers possible
  • Usable for measurements with and without controlled air humidity, and in all liquid media under various biologically relevant conditions
  • Different pairings and contact geometries (ball-on-disk, crossed cylinders)
  • Suitable for long-term studies
  • Normal force range from 1 µN to 1 N, lowest resolution of lateral force • Travel range: 20 mm, velocity: 0.02 to 10 mm/sec, lateral resolution: 1µm

Materials and Dimensions

  • Very hard (e. g. metal, ceramic) to very soft materials (e. g. polymers, biological tissue)
  • Diameter: max. 7 cm
  • Spherical, flat, cylindrical and curved geometries

Contact us – and fathom micro tribology and new aspects of the properties of your product!