Piezoelectric monomorph, which has only one element, is a potential structure for piezoelectric applications in some extreme conditions. But as the restriction of the strain neutral layer, the traditional parallel electrode connection is not effective for sensing and energy harvesting. In this paper, perpendicular electrode connections were designed to utilize the nonuniform shear piezoelectric effect in the cross section of the monomorph, which made the monomorph avoid the restriction of the strain neutral layer. The PZT5 ceramic monomorph was preliminarily studied in this experiment. By comparing seven forms of perpendicular electrode connections with the traditional parallel electrode connection, the whole superposed perpendicular electrode connection is considered as the optimal output way for the monomorph. It can produce 13？V peak-to-peak (pk-pk) voltage in open circuit and 14.56？μW maximum power with the matching resistance, which are much more than the parallel electrode connection 0.78？V and 0.14？μW. 1. Introduction Piezoelectric cantilever is widely used in the piezoelectric device for sensing and energy harvesting [1–6]. At room temperature and ambient pressure, unimorph and bimorph, which utilize the lateral extensional piezoelectric effect, are considered as a promising solution for sensing and energy harvesting [7, 8]. But when both of the above composite structures are used under the relative tough environment, such as high temperature and high pressure or low temperature and low pressure, the stability and performance of the device will be lower as the thermal-oxidative degradation and the low temperature brittleness of the bonding materials between different components. Even in the normal situation, the internal stresses and the permanent strain in the bonding layer will lead to the rapid deterioration of the device after long time using . As for the simplest transducer that has only one piezoelectric component, the piezoelectric monomorph avoids the bonding issues and is considered as the only solution in the extreme conditions. But the existence of the strain neutral layer, which is in the middle of the thickness of the piezoelectric element, neutralizes the positive and negative induced charges . As a result, with the traditional parallel electrode connection, the monomorph is not effective in the piezoelectric applications. In order to improve the performance of the monomorph, many studies have been focused on the nonuniform polarization inside the piezoelectric materials. Based on the nonuniform distribution of the electric
F. Goldschmidtboeing and P. Woias, “Characterization of different beam shapes for piezoelectric energy harvesting,” Journal of Micromechanics and Microengineering, vol. 18, no. 10, Article ID 104013, 2008.
X. Gao, W. H. Shih, and W. Y. Shih, “Induced voltage of piezoelectric unimorph cantilevers of different nonpiezoelectric/piezoelectric length ratios,” Smart Materials and Structures, vol. 18, no. 12, Article ID 125018, 2009.
Y. K. Hong, H. K. Park, S. Q. Lee, K. S. Moon, R. R. Vanga, and M. Levy, “Design and performance of a self-sensing, self-actuating piezoelectric monomorph with interdigitated electrodes,” in Optomechatronic Sensors, Actuators, and Control, vol. 6048 of Proceedings of SPIE, pp. 210–217, October 2004.
Y. K. Hong and K. Moon, “Single crystal piezoelectric transducers to harvest vibration energy,” in Optomechatronic Actuators and Manipulation, vol. 6048 of Proceedings of SPIE, no. 60480E, December 2005.