Towards Nonlinear Magnetic Rotating Pendula for Low-Frequency Weak Vibration Energy Harvesting

Mihai Ionut Trandafir and Panagiotis Alevras ()
Additional contact information
Mihai Ionut Trandafir: School of Production Engineering and Management, Technical University of Crete, 73100 Chania, Greece
Panagiotis Alevras: School of Production Engineering and Management, Technical University of Crete, 73100 Chania, Greece

Energies, 2025, vol. 18, issue 8, 1-22

Abstract: Energy harvesting from ambient vibrations has received significant attention as an alternative renewable, clean energy source for microelectronic devices in diverse applications such as wearables and environmental monitoring. However, typical vibrations in remote environments exhibit ultra-low frequencies with variations and uncertainty leading to operation away from resonance and severe underperformance in terms of power output. Pendulum-based energy harvesters offer a promising solution to these issues, particularly when designed for parametric resonant response to driven displacement of the pendulum pivot. Parametric excitation has been shown to trigger fast rotational motion of the pendulum VEH that is beneficial for energy generation and the necessary space utilization. Nevertheless, low-frequency ambient vibrations typically come at very weak amplitudes, a fact that establishes significant design barriers when traditional gravitational pendula are used for rotary energy harvesting. In this paper, we propose a novel concept that utilizes permanent magnet arrays to establish pendulum dynamics. Extensive investigation of the restoring torque of the proposed magnetic pendulum concept is conducted with analytical tools and FEA verification. The resulting oscillator exhibits frequency tuning that is decoupled from gravity and adjustable via the circularly arranged magnetic fields, leading to increased flexibility in the concurrently necessary amplitude tuning. Numerical integration of the nondimensional equation of motion is performed in the system’s parameter space to identify the impact on the regions triggering rotational response to parametric excitation. Finally, a theoretical case study is numerically investigated with the device space constrained within 20 cm 3 , showing a multi-fold improvement in the achieved power density of over 600 μW/cm 3 /g 2 /Hz over a broad range of frequencies and driving amplitudes as low as 1.1 Hz at 0.2 g.

Keywords: vibration energy harvesting; electromagnetic; pendulum; low frequency; rotational (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/18/8/2058/pdf (application/pdf)
https://www.mdpi.com/1996-1073/18/8/2058/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:18:y:2025:i:8:p:2058-:d:1636442

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().