Vertically Integrated Double Buckled-Bridge for Softening Nonlinear Piezoelectric Energy Harvester

This paper firstly reports a vertically integrated double buckled-bridge for broad bandwidth piezoelectric energy harvester based on the thinned piezoelectric thick films on flexible polymer substrate. A nonuniform distribution of the stiffness in buckled-bridge results in a broad bandwidth compared to state of the art through inducing large deformation, which attributes to a reversible nonlinear mechanism from softening to hardening nonlinear effect. The vertically integrated double-bridge strategy is promising to expand the available three-dimensional space for high-energy output per chip area and improve the structural stability.