Sensors and Actuators A 163 (2010) 493–500 Contents lists available at ScienceDirect Sensors and Actuators A: Physical journal homepage: www.elsevier.com/locate/sna Performance comparison of PZT and PMN–PT piezoceramics for vibration energy harvesting using standard or nonlinear approach Prissana Rakbamrung a , Mickaël Lallart b,∗ , Daniel Guyomar b , Nantakan Muensit a , Chanchana Thanachayanont c , Claude Lucat d , Benoît Guiffard b , Lionel Petit b , Pisan Sukwisut a a Department of Physics, Prince of Songkla University, Songkhla, Thailand b LGEF, INSA-Lyon, 8 rue de la Physique, F-69621, Lyon, France c National Metals and Materials Technology Center, Pathumthanee, Thailand d Laboratoire IMS, Université de Bordeaux I, Talence 33405, France article info Article history: Received 15 February 2010 Received in revised form 18 August 2010 Accepted 18 August 2010 Keywords: Energy harvesting Energy scavenging Piezoelectric Nonlinear Energy conversion PMN–PT PZT abstract This paper reports the performance comparison of two common piezoelectric compositions for energy harvesting purposes, using either a standard or a nonlinear technique. Unlike single crystals, piezoelectric ceramics are quite easy to obtain, and thus their application to realistic applications is feasible. This study focuses on two compositions: PZT + 1 mol% Mn and PMN–25PT, obtained from sintering piezoelectric powders, and highlights the advantages and drawbacks for each of them. Then the obtained samples are evaluated for energy harvesting purposes, either by connecting them directly to the harvesting stage or by adding a nonlinear interface that consists of inverting the piezovoltage synchronously with the structure motion, leading to an artificial increase of the conversion abilities. The piezoceramics show a significant difference in power generation ability when using the classical energy harvesting technique. However, it is demonstrated that the use of the nonlinear treatment on the output voltage of the transducers leads to a great reduction in this discrepancy in spite of the difference in ceramic compositions. © 2010 Elsevier B.V. All rights reserved. 1. Introduction The proliferation of lightweight, portable devices has led to the challenge of supplying electrical energy to these systems [1–4]. Up to now, such an issue has been overcome by the use of primary batteries, that however features maintenance problems due to their limited lifespan, as well as environmental issues because of their complex recycling process. Hence, in order to counteract these problems, the use of micro- generators able to convert ambient energy into useful electrical energy has been proposed and investigated over the last decade. Among the available energy sources (for instance thermal or solar), a particular attention has been placed on vibration energy harvest- ing using piezoelectric elements for the conception of small-scale harvesters [5–7], as these materials feature high energy densities and high integration potentials. The maximization of the output power of such microgener- ators is usually obtained by using piezomaterial featuring high coupling coefficient along the 3–1 axis (flexural mode). Hence, a ∗ Corresponding author. Tel.: +33 472437428. E-mail address: mickael.lallart@insa-lyon.fr (M. Lallart). great effort has been made in past few years in the field of piezo- electric single crystals featuring giant piezoelectric properties [8]. Nevertheless, the conception of such materials is complex and costly, and no industrial process exists up to now. Hence, piezo- ceramics that can feature a much easier fabrication process have been of interest. These include the lead zirconate titanate or PZT ceramic which is well known for various applications, including energy harvesting devices [9]. A small amount of various acceptor dopants such as Mn are sometimes added during the fabrication process in order to enhance its piezoelectric properties. In this domain, it has been reported that the reduction of oxygen vacancy concentration and improvements in PZT fatigue and retention char- acteristics are obtained when small amount of Mn (<1 mol%) is doped into PZT making the PZT + 1 mol% Mn a good trade-off for piezoelectric conversion [10,11]. Another composition of interest is the PT-doped PMN, as such a ceramic is a relaxor-based ferroelec- tric with excellent electromechanical coupling. Compared to PZT, the piezoelectric coefficient of such materials can be increased by a factor up to 3 in lateral mode and exceed 2000 pC N -1 [12,13]. PT is interesting to use as dopant of PMN to adjust the Curie temperature (T C ) of the sample due to the fact that the polarization is disap- pearing over T C . While it has been reported in previous works that the PMN–35PT ceramic exhibits the highest piezoelectric activity 0924-4247/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.sna.2010.08.028