Design and fabrication of acoustic wave actuated microgenerator for portable electronic devices

An acoustic wave actuated microgenerator for power system applications in mobile phone was design, fabricated, and characterized. We used the acoustic wave of human voices or speakerphone by way of an electromagnetic transducer to produce electrical power for charging or to run a portable electronic device. The proposed microgenerator is composed of a planar coil, a suspension plate with supporting beams and a permanent magnet. In this paper, the dynamic response of the suspension structure and the variation of the induced magnetic flux were characterized by using commercial finite element analysis and Ansoft Maxwell EM3D software, respectively. The electroplating nickel and silicon bulk micromachining techniques were used to fabricate the suspension plate and planar coil, and by integrating a permanent magnet as well as wafer to wafer adhesion bonding to accomplish the microgenerator assembly. The experimental results shown the typical microgenerator with a planar dimension of 3 mm times 3 mm, the maximum induce-voltage 0.24 mV was generated at the driving frequency of 470 Hz. The dynamic response of microgenerator can be designed to meet a specific acoustic driving frequency to increase the efficiency of energy harvesting.

[1]  T. S. Birch,et al.  Development of an electromagnetic micro-generator , 1997 .

[2]  N.M. White,et al.  Design and performance of a microelectromagnetic vibration powered generator , 2005, The 13th International Conference on Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05..

[3]  Jason Underwood,et al.  INTEGRATED SOLAR POWER SYSTEMS , 2000 .

[4]  F. Ericson,et al.  Young's Modulus, Yield Strength and Fracture Strength of Microelements Determined by Tensile Testing , 1998 .

[5]  H. Elgamel,et al.  High efficiency polycrystalline silicon solar cells using low temperature PECVD process , 1998 .

[6]  L. S. Stephens,et al.  Mechanical property evaluation and failure analysis of cantilevered LIGA nickel microposts , 2001 .

[7]  Rajeevan Amirtharajah,et al.  Self-powered signal processing using vibration-based power generation , 1998, IEEE J. Solid State Circuits.

[8]  Gordon M. H. Chan,et al.  Infrared signal transmission by a laser-micromachined, vibration-induced power generator , 2000, Proceedings of the 43rd IEEE Midwest Symposium on Circuits and Systems (Cat.No.CH37144).

[9]  G. Wachutka,et al.  Micromachined CMOS thermoelectric generators as on-chip power supply , 2003, TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664).

[10]  Paul K. Wright,et al.  A piezoelectric vibration based generator for wireless electronics , 2004 .

[11]  W. Fang,et al.  Characterization of the bending creep behavior for electroplating nickel microbeam , 2005, 2005 6th International Conference on Electronic Packaging Technology.

[12]  Edoardo Mazza,et al.  Experimental determination of mechanical properties of Ni and Ni-Fe microbars , 1995 .

[13]  Myron A. Jeppesen.  Young's Modulus , 1955 .

[14]  Derek G. Chetwynd,et al.  Investigation of a resonance microgenerator , 2003 .

[15]  David Scheiman,et al.  Integrated solar power systems [space power applications] , 2000, Conference Record of the Twenty-Eighth IEEE Photovoltaic Specialists Conference - 2000 (Cat. No.00CH37036).

[16]  Micromachined thin solar cells with a novel light trapping scheme , 1998 .

[17]  D. Inman,et al.  A Review of Power Harvesting from Vibration using Piezoelectric Materials , 2004 .

[18]  R. B. Yates,et al.  Analysis Of A Micro-electric Generator For Microsystems , 1995, Proceedings of the International Solid-State Sensors and Actuators Conference - TRANSDUCERS '95.

[19]  Kristofer S. J. Pister,et al.  Micro-Electrostatic Vibration-to-Electricity Converters , 2002 .

[20]  T. Bergunde,et al.  European Roadmap of Multijunction Solar Cells and Qualification Status , 2006, 2006 IEEE 4th World Conference on Photovoltaic Energy Conference.

[21]  R. L. Edwards,et al.  Mechanical properties of LIGA-deposited nickel for MEMS transducers , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[22]  Jan M. Rabaey,et al.  A study of low level vibrations as a power source for wireless sensor nodes , 2003, Comput. Commun..

[23]  T.C. Green,et al.  Comparison of SOI power device structures in power converters for high-voltage, low-charge electrostatic microgenerators , 2005, IEEE Transactions on Electron Devices.

[24]  Anantha Chandrakasan,et al.  Vibration-to-electric energy conversion , 1999, Proceedings. 1999 International Symposium on Low Power Electronics and Design (Cat. No.99TH8477).

[25]  Neil M. White,et al.  Towards a piezoelectric vibration-powered microgenerator , 2001 .

[26]  K. Najafi,et al.  An electromagnetic micro power generator for low-frequency environmental vibrations , 2004, 17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest.

[27]  A. Field.  Communications , 1963, The Journal of Asian Studies.