Cantilevered piezoelectric energy harvesters have been extensively investigated in the literature of energy harvesting. As an alternative to conventional cantilevered beams, this article presents the L-shaped beam-mass structure as a new piezoelectric energy harvester configuration. This structure can be tuned to have the first two natural frequencies relatively close to each other, resulting in the possibility of a broader band energy harvesting system. This article describes the important features of the L-shaped piezoelectric energy harvester configuration and develops a linear distributed parameter model for predicting the electromechanically coupled voltage response and displacement response of the harvester structure. After deriving the coupled distributed parameter model, a case study is presented to investigate the electrical power generation performance of the L-shaped energy harvester. A direct application of the L-shaped piezoelectric energy harvester configuration is proposed for use as landing gears in unmanned air vehicle applications and a case study is presented where the results of the L-shaped — energy harvester — landing gear are favorably compared against the published experimental results of a curved beam configuration used for the same purpose.
Anton, S.R. and Sodano, H.A.2007. ``A Review of Power Harvesting using Piezoelectric Materials (2003)-(2006),'' Smart Materials and Structures , 16:R1-R21.
2.
Anton, S.R., Erturk, A. and Inman, D.J.2008. ``Energy Harvesting from Small Unmanned Air Vehicles ,'' In: Proceedings of the 17th International Symposium on Application of Ferroelectrics, 3rd Annual Energy Harvesting Workshop, 24-27 February 2007, Santa Fe, NM.
3.
Arnold, D.P.2007. ``Review of Microscale Magnetic Power Generation , '' IEEE Transactions on Magnetics, 43:3940-3951.
4.
Baker, J.M., Roundy, S. and Wright, P.K.2005. ``Alternative Geometries for Increasing Power Density in Vibration Energy Scavenging for Wireless Sensor Networks,'' In: Proceedings of 3rd International Energy Conversion Engineering Conference, 15-18 August 2005, San Francisco, CA.
5.
Balachandran, B. and Nayfeh, A.H.1990. ``Nonlinear Motions of Beam-mass Structure, '' Nonlinear Dynamics, 1:39-61.
6.
Beeby, S.P., Tudor, M.J. and White, N.M.2006. ``Energy Harvesting Vibration Sources for Microsystems Applications,'' Measurement Science and Technology, 17:175-195.
7.
Chopra, A.2007. Dynamics of Structures: Theory and Applications to Earthquake Engineering, Prentice Hall, New Jersey.
8.
Cook-Chennault, K.A., Thambi, N. and Sastry, A.M.2008. ``Powering MEMS Portable Devices - A Review of Non-regenerative and Regenerative Power Supply Systems with Emphasis on Piezoelectric Energy Harvesting Systems,'' Smart Materials and Structures , 17:043001:1-33.
9.
duToit, N.E., Wardle, B.L. and Kim, S.G.2005. ``Design Considerations for MEMS-scale Piezoelectric Mechanical Vibration Energy Harvesters,'' Journal of Integrated Ferroelectrics , 71:121-160.
10.
Erturk, A., Anton, S.R. and Inman, D.J.2007. ``Energy Harvesting from Rigid Body Motions,'' In: Proceedings of the 18th International Conference of Adaptive Structures and Technologies, 3-5 October 2007, Ottawa, Ontario, Canada.
11.
Erturk, A. and Inman, D.J.2008a. ``A Distributed Parameter Electromechanical Model for Cantilevered Piezoelectric Energy Harvesters,'' ASME Journal of Vibration and Acoustics, 130:041002:1-15.
12.
Erturk, A., Tarazaga, P.A., Farmer, J.R. and Inman, D.J.2008b. ``Effect of Strain Nodes and Electrode Configuration on Piezoelectric Energy Harvesting from Cantilevered Beams,'' ASME Journal of Vibration and Acoustics, 10.1115/1.2981094.
13.
Erturk, A. and Inman, D.J.2008c. ``An Experimentally Validated Bimorph Cantilever Model for Piezoelectric Energy Harvesting from Base Excitations,'' Smart Materials and Structures (in review).
14.
Erturk, A. and Inman, D.J.2008d. ``On Mechanical Modeling of Cantilevered Piezoelectric Vibration Energy Harvesters,'' Journal of Intelligent Material Systems and Structures, 19, 10.1177/1045389X07085639 (in press).
15.
Face® 2008. TH-8R data sheet . URL http://www.faceco.com
16.
Fleming, J., Ng, W. and Ghamaty, S.2002. ``Thermoelectric-based Power System for UAV/MAV Applications ,'' Proceedings of 1st Technical Conference and Workshop in Unmanned Aerospace Vehicles, 20-23 May 2002 , Portsmouth, VA.
17.
Gallington, R.W., Merman, H., Entzminger, J., Francis, M.S., Palmore, P. and Stratakes, J.1996. ``Unmanned Aerial Vehicles,'' Future Aeronautical and Space Systems, AIAA, 172:251-296.
18.
Guyan, R.1965. ``Reduction of Stiffness and Mass Matrices, '' AIAA Journal, 3:380.
19.
Haddow, A.G., Barr, A.D.S. and Mook, D.T.1984. ``Theoretical and Experimental Study of Modal Interaction in a Two-degree-of-freedom Structure,'' Journal of Sound and Vibration, 97:451-473.
20.
Hu, Y., Xue, H. and Hu, H.2007. ``A Piezoelectric Power Harvester with Adjustable Frequency through Axial Preloads,'' Smart Materials and Structures , 16:1961-1966.
21.
Lesieutre, G.A., Ottman, G.K. and Hofmann, H.F.2004. ``Damping as a Result of Piezoelectric Energy Harvesting ,'' Journal of Sound and Vibration, 269:991-1001.
22.
Magoteaux, K.2007. Investigation of an Energy Harvesting Small Unmanned Air Vehicle. Master of Science Thesis, University of Dayton .
23.
Mitcheson, P.D., Miao, P., Start, B.H., Yeatman, E.M., Holmes, A.S. and Green, T.C.2004. ``MEMS Electrostatic Micro-Power Generator for Low Frequency Operation,'' Sensors and Actuators A, 115:523-529.
24.
Nayfeh, A.H. and Mook, D.T.1979. Nonlinear Oscillations, Wiley , New York.
25.
Ottman, G.K., Hofmann, H.F., Bhatt, A.C. and Lesieutre, G.A.2002. ``Adaptive Piezoelectric Energy Harvesting Circuit for Wireless Remote Power Supply,'' IEEE Transactions on Power Electronics, 17:669-676.
26.
Oueini, S.S., Nayfeh, A.H. and Pratt, J.R.1998. ``A Nonlinear Vibration Absorber for Flexible Structures ,'' Nonlinear Dynamics, 15:259-282.
27.
Pines, D.J. and Bohorquez, F.2006. ``Challenges Facing Future Micro-air-vehicle Development ,'' AIAA Journal of Aircraft, 43:290-305.
28.
Priya, S.2007. ``Advances in Energy Harvesting using Low Profile Piezoelectric Transducers,'' Journal of Electroceramics, 19:167-184.
29.
Qidawi, M.A., Thomas, J.P. and Kellogg, J.C.2005. ``Expanding Mission Capabilities of Unmanned Systems through the Collection of Energy in the Field,'' In: Proceedings of the AIAA 3rd International Energy Conversion Engineering Conference , 15-18 August 2008, San Francisco, CA.
30.
Rao, S.S.2007. Vibration of Continuous Systems, Wiley , New York.
31.
Roundy, S.,Wright, P.K. and Rabaey, J.2003. ``A Study of Low Level Vibrations as a Power Source for Wireless Sensor Nodes,'' Computer Communications, 26:1131-1144.
32.
Sodano, H.A., Park, G. and Inman, D.J.2004. ``Estimation of Electric Charge Output for Piezoelectric Energy Harvesting.'' Strain, 40:49-58.
33.
Sodano, H.A., Inman, D.J. and Park, G.2005. ``Generation and Storage of Electricity from Power Harvesting Devices,'' Journal of Intelligent Material Systems and Structures , 16:67-75.
34.
Williams, C.B. and Yates, R.B.1996. ``Analysis of a Micro-electric Generator for Microsystems ,'' Sensors and Actuators A, 52:8-11.
