A novel manufacturing method and structural design of functionally graded piezoelectric composites for energy-harvesting

The power supply to the sensors becomes increasingly critical as the Internet of Things (IoT) evolves. Hence, our goal is to transform ambient environmental energy in our daily lives into electrical energy and then give power to IoT sensors. In this work, we developed and manufactured functionally-graded piezocomposite using poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] and barium titanate (BaTiO3, BTO) particles. Functionally graded materials offer better specific strength, toughness, and fatigue resistance than homogeneous composite materials, making them appropriate for energy-harvesting. Spin coating and hot-pressing methods were used to create BTO/P(VDF-TrFE) composites with varying BTO particle fractions and structures. After determining the optimal spin coating and hot-pressing conditions, the composites were polarized using the corona poling technique. The structure and properties of the composites were determined by scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. Then the piezoelectric characteristics were tested, and impact and vibration energy production tests were devised and carried out. This research provides a feasible manufacturing method for functionally graded piezocomposites and investigates the material energy-harvesting potential. Meanwhile, guidance is offered for the construction of functionally graded piezoelectric composites structures for use in various types of energy-harvesting applications.