MEMS Electret Generator for Energy Harvesting

Y. Feng, K. Hagiwara, Q. Fu, Y. Minakawa, R. Chen, and Y. Suzuki

Overview

Energy harvesting is now attracting much attention targeting at their application to automotive sensors, implantable medical equipments and network nodes for structural health monitoring. Final goal of the present study is to develop vibration-driven MEMS power generation device, which produces electricity from environmental low-frequency vibration.

Whereas electromagnetic induction is used for converting kinetic energy to electricity in macro scale, electrostatic induction is superior in micro scale, where relative speed remains small. In the present study, we employ electrostatic induction using polymer electrets as the power generation principle.

So far, we develop a new fluorinated amorphous polymer material based on CYTOP and demonstrate extremley-high surface charge density above 2 mC/m^2 (at the film thickness of 15 um), which is up to 5 times larger than that of conventional electret materials. In a preliminary experiment, we have obtained 0.7 milli watts power generation at a vibration frequency as low as 20Hz. Novel photoionization charge technologies with soft X-ray and vacuum UV have also been developed.

We develop a novel MEMS process for Parylene high-aspect ratio structure (HARS) for soft but robust HARS spring. We also propose a passive gap-spacing control method using electret in order to avoid stiction between top and bottom substrates. Out-of-plane repulsive force is successfully demonstrated with our early prototype both in air and liquid. By using the present electret-based levitation method to keep the air gap, a MEMS electret generator has been developed for energy harvesting applications. Dual-phase electrode arrangement is adopted in order to reduce the horizontal electrostatic damping force. With the present prototype, the total power output of 4 µW has been obtained at an acceleration of 1 G with 40 Hz. In addition, with the aid of a non-linear polymer spring system, power generation at a broad frequency range of 16-40 Hz has also been demonstrated.

Electrostatic power generation system from unsteady thermal field is also under development.

Sponsor: Next Generation World-Leading Researchers (NEXT Program) (JSPS) [PI: Y. Suzuki]

 

Concept of MEMS Electret Generator

MEMS Electret Generator with Parylene High-aspect-ratio Springs (Suzuki et al., JMM, 2010)

Intermittent Operation of LED Using Electret Generator (Edamoto et al., IEEE MEMS2009)

Recent Report

(Electret-based MEMS Energy Harvester)
  • Matsumoto, K., Saruwatari, K., and Suzuki, Y.,
    “Vibration-powered Battery-less Sensor Node Using Electret Generator,”
    Proc. 11th Int. Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2011), Seoul, pp. 134-137 (2011).
  • Suzuki, Y.,
    "Recent Progress in MEMS Electret Generator for Energy Harvesting,"
    IEEJ Trans. Electr. Electr. Eng., Vol. 6, No. 2, pp. 101-111 (2011).
    (doi: 10.1002/tee.20631)
  • Suzuki, Y., Miki, D., Edamoto, M., and Honzumi, M.,
    “A MEMS Electret Generator With Electrostatic Levitation For Vibration-Driven Energy Harvesting Applications,”
    J. Micromech. Microeng., Vol. 20, Issue. 10, No. 104002, 8pp, (2010).
    (doi:10.1088/0960-1317/20/10/104002)
  • Miki, D., Honzumi, M., Suzuki, Y., and Kasagi, N.,
    "Large-Amplitude MEMS Electret Generator with Nonlinear Spring,"
    23rd IEEE Int. Conf. Micro Electro Mechanical Systems (MEMS2010), Hong Kong, pp.176-179 (2010).

(MEMS Energy Harvester Using Vertical Electret)

  • Yamashita, K., Honzumi, M., Hagiwara, K., Iguchi, Y., and Suzuki, Y.,
    “Vibration-driven MEMS Energy Harvester with Vacuum UV-Charged Vertical Electrets,”
    Proc. 16th Int. Conf. Solid-state Sensors, Actuators, and Microsystems (Transducers ’11), Beijing, pp. 2630-2633 (2011).
  • Yamashita, K., Honzumi, M., Hagiwara, K., Iguchi, Y., and Suzuki, Y.,
    "MEMS Electret Energy Harvester Using Vertical Electrets,"
    Proc. 10th Int. Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2010), Leuven, pp. 165-168 (2010).

(Modeling of Electret Generator)

  • Miki, D., Suzuki, Y., and Kasagi, N.,
    "Effect of Nonlinear External Circuit on Electrostatic Force of Micro Electret Generator,"
    15th Int. Conf. Solid-state Sensors, Actuators, and Microsystems (Transducers' 09), Denver, pp. 636-639 (2009).
  • Marboutin, C., Suzuki, Y., and Kasagi, N.,
    "Optimal Design of Micro Electret Generator for Energy Harvesting,"
    7th Int. Workshop Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2007), Freiburg, pp. 141-144 (2007).

(High-performance Polymer Electret Film)

  • Kashiwagi, K., Okano, K., Miyajima, T., Sera, Y., Tanabe, N., Morizawa, Y., and Suzuki, Y.,
    “Nano-cluster-enhanced High-performance Perfluoro-polymer Electrets for Micro Power Generation,”
    J. Micromech. Microeng., Vol. 21, Issue 12, No. 125016, (2011).
    (doi:10.1088/0960-1317/21/12/125016)
  • Sakane, Y., Suzuki, Y., and Kasagi, N.,
    "Development of High-performance Perfluorinated Polymer Electret and Its Application to Micro Power Generation,"
    J. Micromech. Microeng., Vol. 18, No. 10, 104011, 6pp. (2008).
    (doi: 10.1088/0960-1317/18/10/104011)
  • Tsutsumino, T., Suzuki, Y., Kasagi, N., and Sakane, Y.,
    "Seismic Power Generator Using High-Performance Polymer Electret, "
    19th IEEE Int. Conf. Micro Electro Mechanical Systems (MEMS2006), Istanbul, pp.98-101 (2006).

(Trench-filled Piezoelectric Polymer Electret)

  • Feng, Y., Hagiwara, K., Iguchi, Y., and Suzuki, Y.,
    “Trench-filled Cellular Parylene Structure for Piezoelectric Polymer Electret,”
    25th IEEE Int. Conf. Micro Electro Mechanical Systems (MEMS’12), Paris, (2012), pp. 1189-1192.

(New Charging Method Using Photoionization)

  • Honzumi, M., Hagiwara, K., Iguchi, Y., and Suzuki, Y.,
    "High-Speed Electret Charging Method Using Vacuum UV Irradiation,"
    Appl. Phys. Lett., Vol. 98, 052901, (2011).
    (doi: 10.1063/1.3548866)
  • K. Hagiwara, M. Goto, Y. Iguchi, T. Tajima, Y. Yasuno, H. Kodama, K. Kidokoro, and Y. Suzuki,
    “Electret Charging Method based on X-ray Photoionization for MEMS Applications,”
    14th IEEE Int. Symp. Electrets (ISE14), Montpellier, pp. 13-14 (2011).
  • Hagiwara, K., Honzumi, M., Goto, M., Tajima, T., Yasuno, Y., Kodama, H., Kidokoro, K., Kashiwagi, K., and Suzuki, Y.,
    "Novel Through-substrate Charging Method for Electret Generator Using Soft X-ray Irradiation,"
    9th Int. Workshop Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2009), Washington DC, pp.173-176 (2009).
(MEMS Seismic Structure)
  • Kamezawa, C., Suzuki, Y., and Kasagi, N.,
    "Mechanical Response Evaluation of High-thermally-stable-grade Parylene Spring,"
    22nd IEEE Int. Conf. Micro Electro Mechanical Systems (MEMS2009), Sorrento, pp. 615-618 (2009).
  • Suzuki, Y., and Tai, Y.-C.,
    "Micromachined High-Aspect-Ratio Parylene Spring and Its Application to Low-frequency Accelerometers,"
    J. Microelectromech. Syst., Vol. 15, No. 5, pp. 1364-1370 (2006).
    (doi:10.1109/JMEMS.2006.879706 )

Last update: 2012-4-1