Ultra wide-bandwidth micro energy harvester

An ultra wide-bandwidth resonating thin film PZT MEMS energy harvester has been designed, modeled, fabricated and tested. It harvests energy from parasitic ambient vibration at a wide range of amplitude and frequency via piezoelectric effect. At the present time, the designs of most piezoelectric energy devices have been based on high-Q linear cantilever beams that use the bending strain to generate electrical charge via piezoelectric effect. They suffer from very small bandwidth and low power density which prevents them from practical use. Contrarily, the new design utilizes the tensile stretching strain in doubly-anchored beams. The resultant stiffness nonlinearity due to the stretching provides a passive feedback and consequently a wide-band resonance. This wide bandwidth of resonance enables a robust power generation amid the uncertainty of the input vibration spectrum. The device is micro-fabricated by a combination of surface and bulk micro-machining processes. Released devices are packaged, poled and electro-mechanically tested to verify the wide-bandwidth nonlinear behavior of the system. Two orders of magnitude improvement in bandwidth and power density is demonstrated by comparing the frequency response of the system with that of an equivalent linear harvester with a similar Q-factor.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Hajati, Arman

Advisor dc:contributor.advisor

• Sang-Gook Kim.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/63072

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/63072