C8.1 - Thermo-Electric Energy Harvester for Low-Power Sanitary Applications

AbstractThe demand for energy harvesting technologies has been increasing over the years that can be attributed to its significance to low power applications. One of the key problems associated with the available vibration-based harvester is the maximum peak power can only be achieved when the device frequency matches the source frequency to generate low usable power. Therefore, in this study, a magnetically-tunable hybrid piezoelectric-triboelectric energy harvester (MT-HPTEH) was designed and optimised. Four key design factors: mass placement, triboelectric surface area, extension length and magnetic stiffness were investigated and optimised. The voltage generation from piezoelectric and triboelectric mechanisms was determined individually to understand the effect of each design factor on the mechanisms. An output power of 659 µW at 180 kΩ at 44 Hz was obtained from the optimised MT-HPTEH with a theoretical–experimental discrepancy of less than 10%. The added magnetically-tunable feature enabled the harvester to work at the desired frequency range with an open circuit voltage between 7.800 and 20.314 V and a frequency range from 38 to 54 Hz. This MT-HPTEH can power at least six wireless sensor networks and can be used for low power applications such as RFID tags. Future work may include designing of energy-saving and sustainable harvester.

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A Low Power AC/DC Interface for Wind-Powered Sensor Nodes

Energies ◽

10.3390/en14071823 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1823

Author(s):

Mohammad Haidar ◽

Hussein Chible ◽

Corrado Boragno ◽

Daniele D. Caviglia

Keyword(s):

Low Power ◽

Power Supply ◽

Energy Harvester ◽

Optimization Techniques ◽

Sensor Nodes ◽

Wireless Sensor ◽

Constant Voltage ◽

Interface Circuit ◽

Switching Converter ◽

Input Signals

Sensor nodes have been assigned a lot of tasks in a connected environment that is growing rapidly. The power supply remains a challenge that is not answered convincingly. Energy harvesting is an emerging solution that is being studied to integrate in low power applications such as internet of things (IoT) and wireless sensor networks (WSN). In this work an interface circuit for a novel fluttering wind energy harvester is presented. The system consists of a switching converter controlled by a low power microcontroller. Optimization techniques on the hardware and software level have been implemented, and a prototype is developed for testing. Experiments have been done with generated input signals resulting in up to 67% efficiency for a constant voltage input. Other experiments were conducted in a wind tunnel that showed a transient output that is compatible with the target applications.

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Multi-Stable Magnetic Spring-Based Energy Harvester Subject to Harmonic Excitation: Comparative Study and Experimental Evaluation

Volume 4B: Dynamics, Vibration, and Control ◽

10.1115/imece2018-86157 ◽

2018 ◽

Author(s):

Hieu Nguyen ◽

Hamzeh Bardaweel

Keyword(s):

Energy Harvesting ◽

Kinetic Energy ◽

Comparative Study ◽

Experimental Evaluation ◽

Chaotic Motion ◽

Energy Harvester ◽

Electric Energy ◽

Harmonic Excitation ◽

Jump Frequency ◽

Piezoelectric Elements

The work presented here investigates a unique design platform for multi-stable energy harvesting using only interaction between magnets. A solid cylindrical magnet is levitated between two stationary magnets. Peripheral magnets are positioned around the casing of the energy harvester to create multiple stable positions. Upon external vibration, kinetic energy is converted into electric energy that is extracted using a coil wrapped around the casing of the harvester. A prototype of the multi-stable energy harvester is fabricated. Monostable and bistable configurations are demonstrated and fully characterized in static and dynamic modes. Compared to traditional multi-stable designs the harvester introduced in this work is compact, occupies less volume, and does not require complex circuitry normally needed for multi-stable harvesters involving piezoelectric elements. At 2.5g [m/s2], results from experiment show that the bistable harvester does not outperform the monostable harvester. At this level of acceleration, the bistable harvester exhibits intrawell motion away from jump frequency. Chaotic motion is observed in the bistable harvester when excited close to jump frequency. Interwell motion that yields high displacement amplitudes and velocities is absent at this acceleration.

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Design Optimization of Low Power and Low Frequency Vibration Based MEMS Energy Harvester

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.475-476.1624 ◽

2013 ◽

Vol 475-476 ◽

pp. 1624-1628

Author(s):

Hasnizah Aris ◽

David Fitrio ◽

Jack Singh

Keyword(s):

Low Power ◽

Energy Harvester ◽

Piezoelectric Materials ◽

Geometry Optimization ◽

Low Frequency ◽

Substrate Thickness ◽

Power Harvesting ◽

Low Frequency Vibration ◽

Length Width ◽

Development And Utilization

The development and utilization of different structural materials, optimization of the cantilever geometry and power harvesting circuit are the most commonly methods used to increase the power density of MEMS energy harvester. This paper discusses the cantilever geometry optimization process of low power and low frequency of bimorph MEMS energy harvester. Three piezoelectric materials, ZnO, AlN and PZT are deposited on top and bottom of the cantilever Si substrate. This study focuses on the optimization of the cantilevers length, width, substrate thickness and PZe thickness in order to achieve lower than 600 Hz of resonant frequency. The harvested power for this work is in the range of 0.02 ~ 194.49 nW.

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