Electromagnetic Linear Vibration Energy Harvester Using Sliding Permanent Magnet Array and Ferrofluid as a Lubricant

Micromachines. 2017;8(10):288 DOI 10.3390/mi8100288

 

Journal Homepage

Journal Title: Micromachines

ISSN: 2072-666X (Online)

Publisher: MDPI AG

LCC Subject Category: Technology: Mechanical engineering and machinery

Country of publisher: Switzerland

Language of fulltext: English

Full-text formats available: PDF, HTML, ePUB, XML

 

AUTHORS


Song Hee Chae (Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea)

Suna Ju (Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea)

Yunhee Choi (Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea)

Ye-Eun Chi (Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea)

Chang-Hyeon Ji (Department of Electronic and Electrical Engineering, Ewha Womans University, Seoul 03760, Korea)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 11 weeks

 

Abstract | Full Text

We present an electromagnetic linear vibration energy harvester with an array of rectangular permanent magnets as a springless proof mass. Instead of supporting the magnet assembly with spring element, ferrofluid has been used as a lubricating material. When external vibration is applied laterally to the harvester, magnet assembly slides back and forth on the channel with reduced friction and wear due to ferrofluid, which significantly improves the long-term reliability of the device. Electric power is generated across an array of copper windings formed at the bottom of the aluminum housing. A proof-of-concept harvester has been fabricated and tested with a vibration exciter at various input frequencies and accelerations. For the device where 5 μL of ferrofluid was used for lubrication, maximum output power of 493 μW has been generated, which was 4.37% higher than that without ferrofluid. Long-term reliability improvement due to ferrofluid lubrication has also been verified. For the device with ferrofluid, 1.02% decrease of output power has been observed, in contrast to 59.73% decrease of output power without ferrofluid after 93,600 cycles.