Uncovering the Printability, Morphological, and Functional Properties of Thick Ferroelectric Composites for Next-Generation Low-Cost Scalable Sensors

Herein, new insights into the printability, rheological, morphological, dielectric, and piezoelectric characteristics of microscale thick-film particulate ferroelectric composites are provided. This is achieved by the fabrication and printing of diethylene glycol monoethyl ether acetate (DGMEA)/DI7025/barium titanate (BaTiO3) inks with varying filler content. The effects of DGMEA and BaTiO3 microparticles on the rheological response are investigated using shear, stress frequency dependence, and three-part recovery tests. The structural and morphological characteristics are analyzed using Fourier-transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The functional sensing behavior is investigated through impedance spectroscopy, piezoelectric, and ferroelectric experiments. The dependences of the dielectric and piezoelectric properties of the composites on BaTiO3 volume fraction are reported and analyzed in terms of Yamada model. The best performance is obtained from the composites with 40 vol% BaTiO3 with parallel-layered structured connectivity. The results offer important insights for the future development of new and improved thin film sensors.