A novel lead-free flexible piezoelectric energy harvester structure based on porous BCZT pillars and PDMS was achieved. Compared with 0–3 type piezoelectric composites, where the piezoelectric phase is isolated within the material, ﬂexible piezoelectric energy harvesters based on a three-dimensional interconnected ceramic skeleton are of particular interest due to their high stress transfer capability and high piezoelectric coefficients. Herein, a novel lead-free ﬂexible piezoelectric energy harvester structure based on porous BCZT pillars and PDMS was developed. The effect of porosity on piezoelectric coefficients, ferroelectric properties and energy harvesting performance is investigated in detail. The aligned BCZT-PDMS composite shows great potential in piezoelectric energy harvesting due to excellent piezoelectric properties and stress transfer capability compared with 0–3 type composites. The piezoelectric coefficient and energy harvesting figure of merit are significantly enhanced due to the presence of an aligned pore structure which leads to a high transfer of applied stress into the piezoelectric phase. The highly aligned porosity leads to the creation of a piezoelectric composite exhibits a high output voltage and current. This work therefore expands the applications of porous piezoelectric materials and provides a new strategy for the manufacture of flexible piezoelectric energy harvesters.
Yan Zhang is now a professor at Central South University and the Associate Head of State Key Laboratory of Powder Metallurgy, with research interests including piezoelectric, pyroelectric and ferroelectric materials, and their applications in piezo-electrocatalysis, energy harvesting, and sensing. She obtained her BSc and PhD degrees in Materials Science from Central South University in 2008 and 2013, respectively. She worked at Hunan University from 2014 to 2016. Her PhD work concentrated on the fine adjustment of aligned porous structures and lead-free porous piezoelectric composites for biomedical application. She was a Marie-Skłodowska-Curie Fellow in Mechanical Engineering at University of Bath, working on porous materials, ferroelectrics, and their composites in 2016 to 2019. She has been awarded the Humboldt Research Fellowship for experienced researchers since 2021. She is now a professor at Central South University, with research interests including piezoelectric, pyroelectric and ferroelectric materials and their applications in electrocatalysis, energy harvesting, and sensing.