Working Group 5.11

Nanoforce Metrology for Tactile Sensors

• Overview dimensional standards for micro structures [270 kB]
• Depth-Setting standards for measurement ranges from 1 µm to 5 mm
• Micro-force standards

Micro Force Setting Standards

In cooperation with the Faculty of Electrical Engineering and Information Technology of the Chemnitz University of Technology and the SiMetrics GmbH Silicon micro force setting standards are developed in order to trace back the probing force measurement of stylus instruments. The project aims at creating standards for the probing force range from 1 µN to 50 mN with uncertainty target values of 5 %. The standards consist of calibrated Si cantilevers. Standards with bending stiffnesses of 4, 12, 50, 120 and 900 N/m have been developed and metrologically investigated. Die Normale sind kommerziell erhältlich.

Figure 1: Sketch and photo of a micro force setting standard

With stylus instrument to be examined simple profile measurements on the cantilever have to be made. From the measured beam deflection and the known bending stiffness the probing force can be determinded.The measurements are made with a nano force measurement device consisting of a precision linear transducer and compensation balance. With a probing pin (s. figure 2) , fixed at the linear transducer, the standard to be calibrated which is located on the compensation balance is probed. The resulting probing force is measured by the compensation balance and simultaneously the position of the linear transducer is measured. The vertical position of the compensation balance is kept constant during the whole calibration. Therefore the movement of the probing pin corresponds to the deflection of the cantilever to be calibrated.

	Figure 2: Stylus measurement on a micro force setting standard