State-of-the-Art Review of Next-Generation Floating Photovoltaic Systems from a Materials Design and Advanced Fabrication Perspective with an Emphasis on Additive Manufacturing and Functionally Graded Materials

To overcome the limitations of conventional homogeneous materials in floating photovoltaic (FPV) systems, this review critically examines advanced material-s design strategies and fabrication approaches that enable enhanced durability, reliability, and performance under coupled hydro-mechanical and environmental loading conditions. Although FPV systems provide a scalable solution to land scarcity, their long-term operation is challenged by wind–wave interactions, persistent moisture exposure, thermal cycling, and corrosion-induced degradation, and biofouling, requiring materials capable of accommodating spatially varying and interacting stressors. Functionally graded materials (FGMs) are explored as a promising solution, enabling continuous variation in the composition and microstructure to tailor local mechanical, thermal, and chemical properties within a single structure. Recent research highlights growing interest in additive manufacturing and gradient design, but limited focus on FPV and marine applications. Emphasis is placed on additive manufacturing as a key fabrication route for realizing complex gradient architectures with high precision and design flexibility. Recent advances demonstrate notable improvements in corrosion resistance, fatigue performance, and stress distribution, leading to the enhanced structural integrity and service life of FPV systems. The review further organizes FGM concepts within a design–process–property–performance framework and discusses their application in key FPV subsystems. This review further evaluates the role of multi-physics modelling and digital twin frameworks in linking processing conditions with in-service performance under realistic operating environments. The potential of computational intelligence approaches for predicting thermo-mechanical response, damage evolution, and reliability of graded structures is also discussed. Additionally, emerging challenges related to gradient characterization, standardization, technology qualification and scalability, and large-scale deployment are critically discussed, highlighting key directions for future research and technological development. Overall, FGMs and advanced manufacturing show strong potential to improve FPV durability, fatigue resistance, and corrosion performance.