An Assessment of Thick-Film Piezoresistors on Insulated Steel Substrates

The development of new, inexpensive, robust and miniaturised sensors is continuously being sought and it is believed that thick-film technology can help to achieve these goals. A strain sensor utilising the piezoresistive properties of thick-film resistors is described here. Characterisation of the sensing element has revealed that the gauge factor is significantly higher than that of metal foil strain gauges and the temperature coefficients are generally lower than those found for semiconductor strain gauges. Results show how the gauge factor can be optimised by varying the production parameters.