Piezoelectric energy harvesting using bulk transducers

Self-powered nodes can be developed by harvesting wasted mechanical vibration energy available in the environment. Piezoelectric converters have been found to be most suitable for transforming mechanical energy into electric energy where the charge generation is directly related to the extent to which the element is deformed. This chapter provides the strategy for the selection of the piezoelectric transducer depending upon the frequency and amplitude of the mechanical stress. The figure of merit for the material selection was found to be directly proportional to product (d · g), where d is the piezoelectric strain constant and g is the piezoelectric voltage constant. The criterion for maximization of the product (d · g) was found to be given as, where n is the material constant which is fixed by the magnitude of the piezoelectric and dielectric constants. Results are reported on various devices utilizing piezoelectric bimorph transducers.