Upside – down composites

Piezoelectric materials have a multi-billion dollar impact on the electromechanical transducers market. Their conventional synthesis includes a sintering step (at over 1000 °C) that often hampers direct integration into monolithic devices and confines their applications to heterostructures made using tedious multi-step assembly or to composites with poor electromechanical behavior. Here, we demonstrate a new and easy to scale method for the integration of piezoelectric ceramics at ultra-low temperatures without compromising their functionality. We show that all-ceramic “upside-down” composites with exceptionally high fractions of piezoelectric filler (75 vol. %) and low porosity can be achieved using aqueous dispersion of lithium molybdate as a binder. The method is based only on coating, mixing, moulding and drying sequences. The measured piezoelectric charge coefficient, d33 84 pC·N−1, outperforms any other known composite, whereas the voltage constant, g33 33 mV m·N−1, competes with bulk materials, thus paving the way for versatile applications not previously considered.

Authors:
Nelo Mikko, Siponkoski Tuomo, Kähäri Hanna, Kordas Krisztian, Juuti Jari, Jantunen Heli

Publication type:
A1 Journal article – refereed

Place of publication:

Keywords:
Electroceramics, Functional composites, Low temperature, Piezoelectricity, Sensors

Published:

Full citation:
Mikko Nelo, Tuomo Siponkoski, Hanna Kähäri, Krisztian Kordas, Jari Juuti, Heli Jantunen, Upside – down composites: Fabricating piezoceramics at room temperature, Journal of the European Ceramic Society, Volume 39, Issue 11, 2019, Pages 3301-3306, ISSN 0955-2219, https://doi.org/10.1016/j.jeurceramsoc.2019.04.052

DOI:
https://doi.org/10.1016/j.jeurceramsoc.2019.04.052

Read the publication here:
http://urn.fi/urn:nbn:fi-fe2019091628343