Key features in the development of unimorph stainless steel cantilever with screen‐printed PZT dedicated to energy harvesting applications

The design and processing of vibrational energy harvester based on screen‐printed piezoelectric lead zirconate titanate (Pb(ZrxTi1‐x)O3 (PZT)) are described here. Two different structures, a simple cantilever and a complex zig‐zag geometry made of PZT layer sandwiched between gold electrodes and supported on a metallic stainless steel substrate have been successfully fabricated by screen printing thick film technique. Compared to bulk PZT ceramics, the main limiting features at different scales are porosity, interfaces, and bending issues. The microstructural analysis of the interfaces in the cantilever has highlighted the formation of an interface between the substrate and the bottom electrode which ensures cohesion of the structure but can limit its dynamic. Bending has shown to be dependent on the thickness of the active piezoelectric layer. Dielectric and electromechanical characterizations performed on multilayers, bulk ceramics, and free‐standing screen‐printed disks are compared and discussed on the basis of interface issues.