Development of high pressure sensors using PZT-based thick films

A new type of pressure sensor is presented which is based on the piezoelectric effect principle in screen printed and fired thick-films. The sensitive element, consisting of a circular piezoelectric layer sandwiched in two conductive layers, is screen printed and fired over an alumina substrate, 2 mm thickness and 3 mm diameter. The sensitive element has a structure of a plane capacitor with the piezoelectric film as dielectric and the two conductive layers, based on Pt/Au material, as armatures, device was encapsulated in a stainless steel housing for the dynamic test. The measuring range covers pressure up to MPa while the reaction time is less than 10 μs. The experimental analysis shows, in a measuring range up to 100 MPa, a sensitivity of about 80-110 pC/MPa. The linearity in the range 25-60 MPa is ≤2% FSO while in the range 60-150 MPa is ≤3% FSO.