Abstract
Digital light processing (DLP) is a high-speed, high-precision 3-dimensional (3D) printing technique gaining traction in the fabrication of ceramic composites. However, when printing 0-3 composites containing lead zirconate titanate (PZT) particles, a widely used piezoelectric ceramic, severe density and refractive index mismatches between the 2 phases pose challenges for ink synthesis and the printing process. Here, we systematically and quantitatively optimized DLP printing of PZT composites, streamlining process development and providing a solid theoretical and experimental foundation for broader applications of DLP technology. PZT particles were pretreated with air plasma to improve slurry uniformity and enhance stress transfer at the composite interface, leading to improved chemical modification, mechanical strength, and piezoelectric properties. We investigated the effects of key process parameters on printability and accuracy by analyzing the curing behavior of PZT-polymer composites. A quantitative model of the DLP curing process was introduced. Unlike stereolithography (SLA), DLP curing depth was found to depend on energy dose and light intensity, with higher intensities proving more favorable for printing 0-3 PZT composites. From depth/width-energy curves, optimal process parameters were determined. We designed and fabricated a soft piezoelectric metamaterial-based touch sensor using these parameters, achieving a customized output profile. This work offers critical insights into optimizing DLP for functional materials and expands the potential of 3D-printed piezoelectric composites.