Application of sol-gel deposited thin PZT film for actuation of 1D and 2D scanners

Despite to promising material properties, only few applications of thin (up to 5 μm) piezoelectric PZT layers for actuation purpose of MEMS exist. To investigate actuation properties and application problems, this paper introduces the design, fabrication and characterization of 1D and 2D micro scanners actuated by a sol-gel deposited PZT layer of 1.5 μm thickness. For the manufactured samples, measurements are carried out. After determining the relative dielectric constant of the PZT layer to about 1000 and its piezoelectric constant d₃₁ to 20...45 10^-12 C/N, scanning angles were measured. For the ID scanner, angles between 11° and 35° could be determined, and for the 2D scanning structure 6.5° and 2.5° were observed for 10 V_pp maximum stimulation AC voltage. Deformation of the beams caused by technologically induced strain was found to change the behavior of the actuators. It can both, either decrease the device performance by increase of the mechanical compliance of the beam, or improve the performance by changing sinusoidal oscillation into a buckling-determined “snapping”