Piezo resistive thin film sensor system

Abstract

This paper presents the latest investigations of thin film sensor developments based on amorphous hydrogenated carbon films. The piezo resistive layer is deposited in a plasma enhanced chemical vapour deposition process in a thickness of 4-6 m. The advantage of this film is a excellent tribological behaviour with a hardness of 20-40 GPa and a coefficient of friction of 0,2 as it is well known from the diamond like carbon layers combined with a piezo resistive characteristic. This layer can detect loads without the need of elongation. A special sensor system in the shape of a washer can be easily integrated in screw joints to detect the normal load distribution.