11801 8 archive 1 disk0/00/01/18/01 2008-09-29 23:49:18 2008-09-29 23:49:18 2008-09-29 23:49:18 article show 0 Lo Hsi-wen Lo-H Tai Yu-Chong Tai-Y-C pub cls public Copyright © 2008 Institute of Physics. Received 4 April 2008, in final form 20 June 2008. Published 29 September 2008. Print publication: Issue 10 (October 2008). The authors would like to thank all members from the Caltech Micromachining Laboratory for their assistance on design, fabrication and testing of this device, especially Mr Trevor Ropers for his assistance with equipment and fabrication processes. (Some figures in this article are in colour only in the electronic version) Special Section Containing Invited Papers, 7th International Workshop on Micro and Nanotechnologies for Power Generation and Energy Conversion Applications (PowerMEMS 2007), Freiburg, Germany, 27–29 November 2007. Journal of Micromechanics and Microengineering, 18(10), October 2008. http://www.iop.org/EJ/toc/0960-1317/18/10 n electret power generator is developed using a new electret made of a charged parylene HT® thin-film polymer. Here, parylene HT® is a room-temperature chemical-vapor-deposited thin-film polymer that is MEMS and CMOS compatible. With corona charge implantation, the surface charge density of parylene HT® is measured as high as 3.69 mC m^−2. Moreover, it is found that, with annealing at 400 °C for 1 h before charge implantation, both the long-term stability and the high-temperature reliability of the electret are improved. For the generator, a new design of the stator/rotor is also developed. The new micro electret generator does not require any sophisticated gap-controlling structure such as tethers. With the conformal coating capability of parylene HT®, it is also feasible to have the electret on the rotors, which is made of either a piece of metal or an insulator. The maximum power output, 17.98 µW, is obtained at 50 Hz with an external load of 80 MΩ. For low frequencies, the generator can harvest 7.7 µW at 10 Hz and 8.23 µW at 20 Hz. 2008-10 published Journal of Micromechanics and Microengineering 18 10 Institute of Physics Art. No. 104006 CaltechAUTHORS:LOHjmm08 TRUE 0960-1317 http://resolver.caltech.edu/CaltechAUTHORS:LOHjmm08 http://dx.doi.org/10.1088/0960-1317/18/10/104006 doi http://stacks.iop.org/JMM/18/104006 pub http://www.iop.org/EJ/abstract/0960-1317/18/10/104006 pub [1] Amjadi H 1999 Charge storage in double layers of thermally grown silicon dioxide and APCVD silicon nitride IEEE Trans. Dielectr. Electr. Insul. 6 852-7 (also see IEEE Trans. Electr. Insul.) [2] Beeby S P 2006 Energy harvesting vibration sources for microsystems applications Meas. Sci. Technol. 17 R175 [3] Boland J, Chao Y H, Suzuki Y and Tai Y C 2003 Micro electret power generator IEEE 16th Ann. Int. Conf. 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G 148 337-42 [29] Wu J, Zhang R R, Wu Q and Stevens K K 2003 Environmental vibration assessment and its applications in accelerated tests for medical devices J. Sound Vib. 267 371-83 You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format. CaltechAUTHORS 12299 3 11801 1 application/pdf en public other

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