In this paper, a design methodology for an energy harvesting device will be investigated and results will be presented to
validate the design. The energy harvesting device in the study is 31- unimorph piezoelectric cantilever beam which was
used to convert small amplitude mechanical vibration from a specific machine application into an electrical energy
source that could be used for electronic devices with low power requirements. The primary purpose of the design
methodology is to illustrate a method to design a cantilever beam that is optimized for a particular application. The
methodology will show how the vibration data (frequency and amplitude) from the machine was analyzed and then how
this information was incorporated into the final design of the beam. From the given vibration data a range of frequencies
where the energy harvesting device will generate the greatest amount of energy is determined. The device is then
designed specifically targeting that frequency range. This approach is presented as part of a more general approach to
designing energy harvesters for any application. Also, it will be shown how the thickness and type of materials used for
each layer of cantilever beam were chosen, completely independent of the vibration data, without effecting the over all
Energy harvesting using piezoelectric material is not a new concept, but its small generation capability has not been attractive for mass energy generation. For this reason, little research has been done on the topic.
Recently, wearable computer concepts, as well as small portable electrical devices, are a few motivations that have ignited the study of piezoelectric energy harvesting. The theory behind cantilever type piezoelectric elements is well known, as is the suppression of beam vibrations, but not from the context of extracting energy for later use. In this paper we analyze the governing equations of a unimorph beam in terms of the electrical energy that can be generated from base excitations with an eye toward developing design tools for energy harvesting hardware.