Multi-layer Piezoelectric 0-0-3 Composites

Low curing depths limit the thickness of piezoelectric composite sensors yielding relatively low piezoelectric performance. To increase piezoelectric composite sensitivity, multi-layer composites can be made by solidifying thin layers one on another. The first study investigates an effective method to increase curing depth for higher homogeneity of multi-layer composites. Experiments show that a higher concentration of photoinitiator seems to increase curing depth up to 50% and strongly reduces viscosity, both are highly desired for UV light curable piezoelectric suspensions. The second study manufactures multi-layer piezoelectric composite sensors and examines microstructure, dielectric, mechanical, and piezoelectric properties. Starting with a second layer, layer heights ( \(\le \) 50  \(\upmu \) m) produce a homogeneous microstructure of the composite, but still, Young’s modulus decreases by \(\approx \) 35% per layer. No significant effect on relative permittivity is observed. Piezoelectric performance and sensitivity of multi-layer sensor increase as expected with increasing sensor thickness.