Three Phase Piezoelectric Composites for Energy harvesting applications

Abstract

Piezoelectric materials have found application in wide range of devices from accelerometers to energy harvesters. They have proven their potential and versatility in aerospace, automotive, electronics and biomedical industry. Piezoelectric ceramics are not suitable for energy harvesting applications due to its brittleness and low strain levels, although having a high piezoelectric charge constant (d33). The polymer based piezoelectric composites offers high flexibility with low dielectric constant, hence having potential application in energy harvesting systems. Currently quasi-structured and fiber based piezoelectric composites offer the highest piezoelectric properties having the required flexibility for energy harvesting application. The polling processes of these composites though, are not so efficient due to the dielectric mismatch between the ceramic filer and surrounding polymer matrix. This leads to low piezoelectric charge constant than theoretically possible. To avoid this dielectric mismatch, dielectric constant cermic filler is added to get the required chain like particle structuring. The decrease in dielectric mismatch would lead to better poling due to increase in the active electric field experienced by the ceramic filler. The work here majorly focuses on development of a 3 phase piezoelectric composites having two different types of ceramic filers. Barium Titanate (BT) nanoparticles were added into a two phase Lead Zirconate Titanate (PZT)/Epoxy composite and were characterized to evaluate piezoelectric properties and particle structuring. The particle size effects of BT nanoparticles were also investigated.