Piezoelectric Energy Harvesting: Modeling, Design, Fabrication, and Testing
Ibrahim (Abe) M. Elfadel Khalifa University, Abu Dhabi, UAE
Micro piezoelectric energy transducers fabricated using wafer-scale micromachining technologies are among the most likely candidates for achieving sensor energy autonomy in such emerging applications as the Industrial Internet of Things, Infrastructure Health Monitoring, Transportation, and Wearable Medical Sensors. The academic and industrial interest in such micro energy sources stems from their small footprint and the economy of scale of their fabrication, which will contribute to lowering their cost to the point of ubiquitous use in the edge devices of the Internet of Things. This tutorial is dedicated to a detailed introduction to the state of the art in the modeling, design, fabrication, and testing of micromachined piezoelectric energy transducers. The topics covered in this tutorial are unique in that they are all based on the lessons learned from the design, fabrication, and testing of three generations of piezoelectric energy transducers with the goal of improving their output power density while satisfying technology cross section and design rule constraints. We will put particular emphasis on power density improvement based on the design of broadband energy transducers using multiple proof masses on cantilever beams or the nonlinear behavior of doubly clamped beams. We also stress the limitations imposed on the output power density by the transducer cavity geometry, its residual gas pressure after vacuum bonding, and the residual stresses in the multilayer vibrating element. In addition, the development of compact electromechanical transducer models is covered so as to enable the co-design and optimization of the micro energy transducer and its electronic interface in a CMOS-MEMS co-design environment. Furthermore, the tutorial will expose the practical considerations for improving the yield in wafer-scale fabrication and how they may impact the output power density of the energy transducer. The tutorial will end with a case study of using piezoelectric energy transducers for powering road-embedded LED’s to improve traffic safety on bridges under night or foggy conditions.
Dr. Ibrahim (Abe) Elfadel is Professor of Electrical and Computer Engineering at the Masdar Institute, Khalifa University of Science and Technology, Abu Dhabi, UAE. Since May 2013, he has been the founding codirector of the Abu Dhabi Center of Excellence on Energy-Efficient Electronic Systems (ACE4 S), and since May 2014, he has been the Program Manager of TwinLab MEMS, a joint collaboration with GLOBALFOUNDRIES and the Singapore Institute of Microelectronics on microelectromechanical systems. Between November 2012 and October 2015, he was the founding co-director of Mubadala’s TwinLab 3DSC, a joint research center on 3D integrated circuits with the Technical University of Dresden, Germany. He also headed the Masdar Institute Center for Microsystems (iMicro) from November 2013 until March 2016. Between 1996 and 2010, he was with the corporate CAD organizations at IBM Research and the IBM Systems and Technology Group, Yorktown Heights, NY, where he was involved in the research, development, and deployment of CAD tools and methodologies for IBM’s high-end microprocessors. In addition to energy harvesting and IoT platform prototyping, his current research interests include energy-efficient IoT communications; energy-efficient edge and cloud computing; power and thermal management of multi-core processors; low-power, embedded digital-signal processing; 3D integration; and CAD for VLSI, MEMS, and Silicon Photonics. Dr. Elfadel is the recipient of six Invention Achievement Awards, one Outstanding Technical Achievement Award and one Research Division Award, all from IBM, for his contributions in the area of VLSI CAD. He is the inventor or coinventor of 50 issued US patents, with several others pending. In 2014, he was the co-recipient of the D. O. Pederson Best Paper Award from the IEEE Transactions on Computer-Aided Design Automation for Integrated Circuits and Systems. He is also the co-editor (with Prof. Gerhard Fettweis) of “3D Stacked Chips: From Emerging Processes to Heterogeneous Systems,” Springer, 2016, and the co-editor (with Prof. Mohammed Ismail) of the upcoming “The IoT Physical Layer: Design and Implementation,” Springer, 2018. Between 2009 and 2013, Dr. Elfadel served as an Associate Editor of the IEEE Transactions on Computer-Aided Design. He is currently serving as Associate Editor of the IEEE Transactions on VLSI Systems and on the Editorial Board of the Microelectronics Journal (Elsevier). Dr. Elfadel has also served on the Technical Program Committees of several top conferences, including DAC, ICCAD, ASPDAC, DATE, ICCD, ICECS, and MWSCAS. Most recently, he was the General Co-chair of the IFIP/IEEE 25th International Conference on Very Large Scale Integration (VLSI-SoC 2017), Abu Dhabi, UAE, October 2017. He received his PhD from MIT in 1993.