Affiliations: [a] School of Mechanical Engineering, Zhengzhou
University, Zhengzhou, Henan, China | [b] Physical Engineering College, Zhengzhou University,
Zhengzhou, Henan, China | [c] Electrical and Computer Engineering, University of
British Columbia, Vancouver, BC, Canada
Correspondence:
[*]
Corresponding author: Yufeng Su, School of Mechanical
Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China. E-mail:
yufengsu@zzu.edu.cn
Abstract: This paper presents theoretical analysis and verification of a micro
vibration energy harvester based on magnetic levitation using diamagnetic
structures. The analysis verifies that diamagnetic material experiences
anti-magnetic force in magnetic field and that it can be used for stable
magnetic levitation. This study proposes a novel design that is comprised of a
lifting permanent magnet, an upper pyrolytic graphite sheet, a floating
permanent magnet, and a lower pyrolytic graphite sheet, with copper spiral
coils formed on the two pyrolytic graphite sheets. The gravity of the floating
permanent magnet is balanced by the attractive force between the lifting and
floating magnets. The diamagnetic force exerted on the levitated magnet by the
two pyrolytic graphite sheets serves as a restoring force, forcing the floating
permanent magnet return to the equilibrium position. Through finite element
analysis, the maximum movable range of the floating magnet is defined to be 1.3
mm. Comparative analysis of the attractive magnetic force and the anti-magnetic
force is performed to determine the key parameters of the structure. The
characteristics of vertical and horizontal motion of the magnet are also
studied in detail. The results validate the effectiveness of the proposed
design for harvesting multi-dimensional, low-frequency vibration energy. The
diamagnetic levitation mechanism without conventional mechanical suspensions
eliminates loss of vibration energy and resultant thermal issues. The system is
potentially promising, through further miniaturization, in providing
sustainable power for micro-electro-mechanical systems.
Keywords: Micro-vibration energy harvester, diamagnetic, levitation, multi-dimension, micro-electro-mechanical system (MEMS)
