A cantilevered piezoelectric bi-stable composite concept for broadband energy harvesting

Recently, the idea to exploit nonlinearity to achieve broadband energy harvesting has been introduced. Bi-stable systems have been used to realise broadband energy harvesting devices. Amongst these, harvesters constructed with bi-stable composites show great potential due to their rich dynamic behaviour. This paper studies a novel cantilevered configuration for a piezoelectric bi-stable composite device for broadband energy harvesting. The cantilevered configuration allows to exploit high strains developed close to the clamped root, further enhancing the harvesting characteristic of bi-stable composites. Furthermore, the desired broadband dynamics are obtained for lower input amplitudes when compared to previous designs constituting a significant improvement for energy harvesting applications. Several cross-well dynamic behaviours are obtained over a relatively wide range of frequencies with the proposed design. In addition, the performance of the developed concept is investigated using a switching shunt harvesting circuit suitable for conversion of broadband oscillations resulting from the cross-well dynamics exhibited by bi-stable composite laminates showing very good results.