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

Abstract

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 730 nW at the resonant frequency of 1.5 kHz with the vibration acceleration of 9.8 m/s 2 . The size of the harvester was smaller than 1 mm 3 . The output power well agrees with the designed value and is sufficient to drive the communication chip with the intermittent mode.

Highly Sensitive Wireless Sensor Node Using Surface Acoustic Wave Devices for Structural Health Monitoring

“…It is desirable to measure all the time to monitor deterioration of large public facilities, but intermittent operation is regarded as the most useful approach from the view of power supply. If intermittent timing is adjusted properly, a battery‐free system could be achieved using energy harvester, which takes the advantage of environmental oscillation .…”

Electromechanical dynamics of Z-shaped mechatronic synchronized switch harvesting on inductor (SSHI) harvester

“…3,4) To shorten the data transmission period of the wireless sensor nodes, the output powers of the VEHs must increase. 5) With the aim of enhancing the mechanical-electrical energy conversion efficiency in standard AC-DC circuits, a synchronized switch harvesting on inductor (SSHI) circuit that uses a component set composed of an active switch and an inductor was developed. [6][7][8] When the switch turns on at each maximum or minimum tip displacement of the harvester, the piezoelectric voltage is inverted rapidly by the inductorcapacitor (LC) electrical oscillation caused between the inductor and the piezoelectric capacitance, thus boosting the piezoelectric voltage and increasing the output voltage/ power.…”