Micromachined silicon sensor for tribological investigations

The design and fabrication procedure of a micromachined silicon sensor applicable for testing surface roughness are presented. The sensor reading principle is based on HF impedance measuring method allowing precise distance measurements of small distances. Using the sensor it is possible to obtain an integral value of the capacitance of some limited part of the object under test in a way in which this capacitance depends on the surface roughness at the tested position. This measurement approach is especially convenient for fast and easy determination of the surface roughness of small sintered objects.