AUTHOR=Hussain Fayaz , Khesro Amir , Lu Zhilun , Wang Ge , Wang Dawei 

TITLE=Lead Free Multilayer Piezoelectric Actuators by Economically New Approach

JOURNAL=Frontiers in Materials

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2020.00087

DOI=10.3389/fmats.2020.00087

ISSN=2296-8016

ABSTRACT=<p>The replacement of lead zirconate titanate ceramics (PZTs), with a lead-oxide (PbO)-free alternative is the subject of intense investigation worldwide. In this research, a cheap reliable methodology for the fabrication of multilayers (MLs) of lead-free potassium sodium niobate (KNN)-based ceramics is presented without the need for vacuuming and/or hot isostatic pressing of the tape. The thickness per active layer was 193 μm and 102 μm for the 10 and 16 layer MLs actuators, respectively. Effective d<sub>33</sub> (piezoelectric coefficient), effective d<sub>33</sub><sup>∗</sup> (electrostrain coefficient), bi-polar strain (S<sub>max</sub>), max displacement, dielectric constant (ϵ<sub>r</sub>) and loss (tanδ) are 2500 pC/N, 4604 pm/V, 0.17%, 2.2 μm, 1812 and 2% at 1 kHz, respectively, where the effective d<sub>33</sub> or d<sub>33</sub><sup>∗</sup> is the total output of all layers together. The ultimate target materials for potential substitution with KNN-based ceramics and MLs are commercial PZT-4 and PZT-8.</p>