Synthesis of PMN-PT/PDMS Piezoelectric Composite for Energy Harvesting

Research in renewable and clean energy has reached an unprecedented magnitude owing to the growing concerns over environmental hazards caused by the traditional fuels. In this regard, solar, wind and tidal energies are considered to meet large scale energy requirements. Small, stand-alone electronic devices which are growing in numbers in next generation smart cities, can be powered by scavenging energy from sources which would otherwise remain unused, such as mechanical vibrations. The source of mechanical vibration could have diverse origins, ranging from vibrations of machines to flow of wind, motion of automobiles, and human footfall etc. Energy harvesting from the above sources can be achieved through the principle of piezoelectricity. In the present work, piezoelectric ceramic ( 1-x ) Pb (Mg 1/3 Nb 2/3 O 3 )- x PbTiO 3 at x = 0.3 was prepared using conventional solid state method. Lead magnesium niobate and lead titanate (PMN-PT) solid solution within the morphotropic phase boundary composition considerably fulfils the essential piezoelectric characteristics for a high energy density harvester. However, PMN-PT is brittle and thus difficult to assemble directly into an energy harvesting system. Hence flexible piezoelectric composite of 20 wt % PMN-PT and polydimethylsiloxane (PDMS) was fabricated to evaluate its energy harvesting capability. Structural and microstructural characterization of the synthesized composite were performed using x-ray diffraction and optical microscopy. Electrical characterization was carried out using Keithley 6517B high resistance electrometer.