One-step firing for electroded PZT thick films applied to MEMS

Free-standing electroded piezoelectric thick-films are straightforwardly fabricated thanks to the association of the low-cost screen-printing technology to the sacrificial layer method. After subsequent printing and drying of a stack of sacrificial, Au, PZT and Au layers on an alumina substrate, the final firing is performed at 900 degrees C. Then, the partial or total releasing step of the Au/PZT/Au is achieved in a diluted acidic solution. Bridges (3.3 x 3.3 x 0.080 mm(3)) and cantilevers (8 x 2 x 0.09 mm(3)) are directly attached to the alumina substrate on top of which they are processed. Studies of the electromechanical behavior of these components show the influence of both the releasing and the densification processes on the piezoelectric properties of the final component. Cantilevers fabricated with this method exhibit favourable properties for sensing applications.