Maximizing the voltage output of piezoelectric arrays via base layer compatibility

Piezoelectric energy harvesting, i.e. the interconversion of electrical and mechanical energy, has the potential to revolutionise how we generate sustainable power for electronic devices. Currently the majority of research into maximising the electrical output of piezoelectrics focuses on the material itself i.e. modulating the electromechanical properties via stoichiometry, crystal engineering, deposition technique, etc. Here we take a different approach, demonstrating that for direct force harvesting the base layer onto which piezoelectrics are mounted has a huge impact on the voltage output of commercial piezoelectric transducers. We almost triple the open-circuit voltage output of a small piezoelectric array from 2.8 to 7.5 Volts by changing the flexibility of the material they are adhered to. As well as conventional base layer materials we use a variety of 3D-printed geometries, which offer a low-cost and efficient method for controlling the dynamics of a piezoelectric-based interface. The goal is that by demonstrating this phenomenon using widely used lead-based piezoelectrics, that it can be utilised for increasing the power output of sustainable alternatives.