Design and realization of high performance textured lead-free piezoelectric ceramics through human-AI collaboration

Developing multielement doped Pb-free (K,Na)NbO₃ piezoelectrics often hindered by complex doping trends and tedious trial-and-error experimentation. Here, we present a human-in-the-loop, artificial intelligence guided materials design framework that utilizes large language models to capture implicit structure-property knowledge from prior literatures and propose new compositions. Expert intervention further directs experimental realization based on materials science principles and experiential knowledge, accelerating discovery of targeted compositions. Using collaborative strategy, synthesized random composition exhibiting piezoelectric charge constant d₃₃ of 440 - 500 pC/N which further enhanced to 600-620 pC/N through crystallographic texturing and sintering aid optimization. Despite inherently off-MPB degradation (at R.T), this composition maintained steady electromechanical coupling (k_ij) and d₃₁ up to 160 ^oC. To validate practical relevance, a cantilever-based magneto-mechano-electric (MME) energy harvester was fabricated, delivering a power density of ~ 705μW/cm³ at the second harmonic, outperforming reported Pb-free MME designs. Here, we demonstrate an exceptional approach towards developing application-specific functional materials through the synergy of AI-driven recommender systems, human expert validation, and experimental realization.