title: Microfabrication and integration of a sol-gel PZT folded spring energy harvester.
abstract: This paper presents the methodology and challenges experienced in the microfabrication, packaging, and integration of a fixed-fixed folded spring piezoelectric energy harvester. A variety of challenges were overcome in the fabrication of the energy harvesters, such as the diagnosis and rectification of sol-gel PZT film quality and adhesion issues. A packaging and integration methodology was developed to allow for the characterizing the harvesters under a base vibration. The conditioning circuitry developed allowed for a complete energy harvesting system, consisting a harvester, a voltage doubler, a voltage regulator and a NiMH battery. A feasibility study was undertaken with the designed conditioning circuitry to determine the effect of the input parameters on the overall performance of the circuit. It was found that the maximum efficiency does not correlate to the maximum charging current supplied to the battery. The efficiency and charging current must be balanced to achieve a high output and a reasonable output current. The development of the complete energy harvesting system allows for the direct integration of the energy harvesting technology into existing power management schemes for wireless sensing.
authors.affiliation: Department of Mechanical Engineering, University of Alberta, University of Alberta, Edmonton, AB T6G 2G8, Canada. lueke@ualberta.ca.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lueke
authors.affiliation: Department of Electrical and Computer, University of Alberta, University of Alberta, Edmonton, AB T6G 2V4, Canada. abadr@ualberta.ca.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Badr
authors.affiliation: Department of Electrical and Computer, University of Alberta, University of Alberta, Edmonton, AB T6G 2V4, Canada. elou@ualberta.ca.
authors.forename: Edmond
authors.initials: E
authors.lastname: Lou
authors.affiliation: Department of Mechanical Engineering, University of Alberta, University of Alberta, Edmonton, AB T6G 2G8, Canada. Walied.Moussa@ualberta.ca.
authors.forename: Walied A
authors.initials: WA
authors.lastname: Moussa
keywords: MEMS; PZT sol-gel; conditioning circuitry; feasibility study; integration; microfabrication; packaging; piezoelectric energy harvesting