From waste to power: Lifecycle-optimised biodegradable piezoelectric systems for sustainable energy harvesting

Flexible piezoelectric materials (FPMs) have emerged as promising candidates for low-power energy harvesting in wearable and ambient sensing applications due to their mechanical flexibility and environmental compatibility. This study evaluates the energy-harvesting performance of monolayer and multilayer FPM structures under controlled laboratory conditions, analysing the effects of mechanical loading, excitation frequency, environmental factors, and structural configuration on electrical output, efficiency, and durability. Experimental results demonstrate that multilayer configurations achieve superior electrical performance and improved stability under cyclic loading, with peak energy conversion efficiencies of approximately 18% observed under optimised strain conditions and stable operation within the low-frequency range (1–5 Hz) relevant to human motion. A hybrid Genetic Algorithm–Particle Swarm Optimisation (GA–PSO) framework is employed to optimise structural and operational parameters, enabling improved energy output while maintaining material durability. In addition, a Lifecycle Sustainability Index (LSI) is introduced to evaluate the environmental performance of FPM systems in terms of energy efficiency, carbon reduction, and waste minimisation. This study uniquely integrates computational optimisation with lifecycle sustainability modelling, establishing a quantitative link between material-level energy harvesting performance and supply-chain circularity. The findings demonstrate that PVDF-based biodegradable polymer composites can achieve functional performance while supporting sustainable manufacturing and circular economy objectives.