New output power estimation method for cantilever-based piezoelectric energy harvesters

In this report, we describe a new estimation method of output power for cantilever-based piezoelectric energy harvesters (CPEHs). To practically apply the energy harvester as an electronic component, on the basis of the vibration mode function, a design equation taking into account not only the output power but also the size and vibration conditions was newly proposed. Using the equation, an energy harvester was designed and fabricated to drive the communication chip based on IEEE 802.15.4. As a result, we succeeded in developing the energy harvester that had the output power of 730nW at the resonant frequency of 1.5 kHz with the vibration acceleration of 9.8m/s2. The size of the harvester was smaller than 1mm3. The output power well agrees with the designed value and is sufficient to drive the communication chip with the intermittent mode.