Repulsively driven frequency-increased-generators for durable energy harvesting from ultra-low frequency vibration

Area of Science:

• Energy Harvesting
• Mechanical Engineering
• Materials Science

Background:

• Traditional energy harvesters struggle with ultra-low-frequency vibrations.
• Efficient conversion of ambient kinetic energy remains a challenge for powering small devices.

Purpose of the Study:

• To develop an electromagnetic kinetic energy harvester capable of converting ultra-low-frequency motion and vibration into electrical power.
• To design a device that utilizes a two-stage vibratory structure and non-contact magnetic forces for enhanced energy conversion efficiency and durability.

Main Methods:

• A two-stage vibratory structure was designed, incorporating a 1st-stage sliding vibrator and 2nd-stage high-frequency resonant generators.
• Non-contact magnetic repulsive force was employed to drive the resonators and achieve frequency-up-conversion resonance.
• A prototype device was fabricated and experimentally tested to validate the design and performance.

Main Results:

• The harvester demonstrated successful operation at frequencies as low as 0.25 Hz.
• Under a 1 g acceleration at 0.5 Hz, the miniaturized device generated a peak power of 4.42 mW and an average power of 158 μW.
• Experimental tests confirmed the design's effectiveness and the device's ability to convert low-frequency kinetic energy.

Conclusions:

• The developed electromagnetic kinetic energy harvester effectively converts ultra-low-frequency motion into usable electrical power.
• The non-contact magnetic actuation ensures a durable and long-lasting device.
• This technology offers a promising solution for powering low-power electronic devices using ambient vibrations.