Manufacturing of a wear detecting sensor made of 17-4PH steel using standard wafer processing technology

A sensor to measure wear of the barrel wall in large ship's Diesel engines is presented. The sensor is a bolt made of steel, which is embedded in and abraded together with the barrel wall. The heart of the sensor is a steel chip supporting a conductive layer between two insulating layers. The conductive layer is structured in the form of resistive loops which are interrupted one after the other when the wall is abraded. Material loss is measured with a resolution of 10 μm over a total length of 3 mm. The sensor will be used to allow longer maintenance intervals for ships, this way reducing downtime and saving cost.