Environment-friendly technologies with lead-free piezoelectric materials: A review of recent developments, applications, and modelling approaches

TL;DR

Environmental concerns surrounding lead-based piezoelectrics motivate a comprehensive review of lead-free alternatives. The paper surveys material families (e.g., KNN, BNT, BT, Li-doped), synthesis routes, properties, and broad applications, and highlights phase-boundary engineering and domain-structure control as means to boost performance. It then outlines theoretical frameworks and multiscale computational methods, including electromechanical, thermo-electromechanical, and phase-field models, coupled with homogenization and FFT-based approaches, complemented by AI-driven discovery and optimization. The work emphasizes how advanced modelling and data-driven strategies can accelerate the design, integration, and deployment of eco-friendly piezoelectric devices for energy harvesting, sensing, actuation, biomedicine, and flexible electronics, contributing to sustainable technology development.

Abstract

Piezoelectric materials are widely used in several industries, including power sources, energy harvesting, biomedical, electronics, haptic, photostrictive, and sensor/actuator technologies. Conventional piezoelectric materials, such lead zirconate titanate (PZT), pose significant environmental and health risks due to lead content. Recent years have seen a growing need for eco-friendly alternatives to lead-based piezoelectric technologies. The drawback of lead-free piezoelectric materials is a reduced responsiveness. To enhance the performance of lead-free piezoelectric materials, substantial research is being undertaken using both experimental and numerical methods. The experimental studies provide a deep understanding of the process and are crucial for developing lead-free piezoelectric materials. Relying only on experimental research is not feasible due to high expenditures. To understand the piezoelectric properties of lead-free materials and enhance their efficiency, it is crucial to develop varied numerical models and computational methods. This paper is a comprehensive summary of lead-free piezoelectric technology breakthroughs. The study emphasizes numerical models that demonstrate enhanced piezoelectric behaviour and their use in eco-friendly technologies like energy harvesting, haptics, nano-electromechanical, photostrictive, and biomedical sensors and actuators using lead-free materials. The paper discusses the synthesis, properties, and applications of eco-friendly materials, highlighting their potential to revolutionize piezoelectric devices and promote sustainable development and conservation.

Figures (3)

• Figure 1: Schematic diagram of principal types of piezoelectric materials
• Figure 2: Bar charts showing the four Figures of Merit for the piezoelectric coefficients of all materials analyzed. The top-left plot presents the maximum longitudinal piezoelectric coefficient, $|e^N_{n\parallel}|_{\max}$, for all materials, while the top-right plot zooms in on values exceeding $1~\mathrm{C}/\mathrm{m}^2$. The bottom row provides details for $|e^N_{n\perp}|_{\max}$, $|e^S_{n\parallel}|_{\max}$, and $|e^S_{n\perp}|_{\max}$.
• Figure 3: Schematic diagram of various applications of lead-free piezoelectric materials