Matthew Bajorek conducted an experiment on vibrational energy harvesting through the electroosmotic effect. He used a glass microchannel array coated with gold electrodes, deionized water, and a speaker to induce vibrations. Testing from 0-100 Hz showed maximum current peaks at 4 Hz, with an efficiency of 0.11% capturing energy from the speaker's 61W output. Future work could improve efficiency by removing air from the system and using a higher resolution measurement device. This technique shows potential for electro-osmotic AC current generation using a smaller apparatus without fluid recycling.

1. Matthew Bajorek, Advisor: F. Javier Diez
Department of Mechanical and Aerospace Engineering, Rutgers – The State University of New Jersey
Results
Conclusion
Acknowledgements & References
Method
Schematic of Experimental Set-up
I would like to thank Dr. F.J Diez and Thomas Hansen for their leadership throughout the project. Also
Rutgers University’s JJ Slade program for the ability to perform independent research as an
undergraduate student.
References:
[1] Abraham Mansouri, Subir Bhattacharjee, Larry Kostiuk, High-power electrokinetic energy conversion
in a glass microchannel array, Lab on a Chip, 2012
Motivation
• Electro-osmotic DC power generation experimental studies have
been showing low-efficiency and low-power generation. A
recent experiment has shown the potential of greater efficiency
with nano-layers of gold that serve as electrodes and using
deionized water.
Unidirectional pressure induced flow through glass
microchannel arrays have been studied and has been limited
in application. However, bidirectional pressure induced flow
induced by vibrations can be harvested electronically while
mechanically dampening the system.
Vibrational Energy Harvesting by the Electroosmotic Effect
Experimental Apparatus [1]
• Electro-osmotic power generation is made possible by a
physical phenomenon occurring within the pores of the
membrane known as the electrical double layer. The outer of
the two layers, known as the diffuse layer, is comprised of ions
and is attracted to the inner layer via Coulumb force. The
diffuse layer is weakly bonded and therefore it can become be
pumped through the membrane. As the charge builds up on
one side, it becomes easier for the electrons to travel through
the conductive electrodes to the other side than to travel back
through the membrane.
Overview of Experiments Conducted:
• Tests were performed from 0-100 Hz.
• Constant voltage was applied to the speaker by adjusting function generator
and amplitude outputs for each frequency.
• Working fluid was deionized water.
• Measured maximum current peaks by sampling of Keithley ammeter.
Membrane Assembly:
• Photonics glass microchannel arrays with a pore diameter of 100 µm were used
because previous successful results from [1]
• The 1 cm2 GMA was epoxied between to an 1/8 in acrylic piece and coated with
60 nm of gold on each side.
• It was then mounted in a between a machined acrylic enclosure fastened by
aluminum bolts.
• Sealing of the pump chamber was achieved with silicone rubber gaskets.
• Visible resonance of the system occurs at a low frequencies with an optimal average
power production at 4 Hz.
• Speaker had a constant output power of 61W. Experimental maximum efficiency
achieved was 0.11%
• Much of the efficiency was lost to mechanical vibrations of the tubes and water.
• In future research, the removal of air and purity of deionized water will be improved
to increase efficiency. Also using a high resolution oscilloscope that would be able
to resolve small currents and voltages would help improve accuracy.
Membrane Assembly
Introduction
• This experiment can be extended to electro-osmotic AC
current generation which allows for a smaller apparatus
because the fluid does not need to be recycled.
Speaker Assembly
Testing Equipment:
• The speaker frequency was generated by a Tekronix CFG200 Function Generator.
• The function was then amplified by an AudioSource AMP 100 Stereo Power
Amplifier.
• The waveforms were monitored by a HP 54601B Oscilloscope.
• The current was measured across the 0.1Ω load resistor by a Keithley 6517B
ammeter.
• A PVC fluid reservoir was use to remove the air from the system and to serve as
storage for the alternating fluid flow.
• A bourdon gauge was used to monitor pressure
• A 4Ω water speaker.
Calculated root mean square
current from the peak current
measured by the ammeter
through the 0.1Ω load resistor
from 0 – 8 Hz. Higher
frequencies did not have
significant current production
Calculated average power density
of the GMA from the root mean
square current. The test had air
trapped so fluid only went
through half of the membrane, so
GMA area of 0.5 cm2 was used in
the calculation.
Visual representation of the components of the
Electrical Double Layer