Finite Element Method Based Performance Analysis of Piezoelectric Materials for Nanogenerator Applications

Demonstrated through this work is the analysis of piezoelectric behavior of wide band gap materials like ZnO, CdS, BaTiO₃, LiNbO₃, AlN and PZT for potential application in nano generators. Nano rods of finite dimensions in the form of perfect cylinders were modeled with conventional PZT used in energy harvesting applications and the alternatives like ZnO, BaTiO₃, ZnO, AlN, LiNbO₃ and CdS whose performance potential and advantages are explained through this work on the basis of analytical and simulation based approaches. Piezoelectric potentials of cylindrical nano rods with two different lengths i.e. 500nm and 600nm and varying diameters were analyzed and the results showed perfect alignment in both numerical and simulation with a minor variation of 7 percent. The potential application of these nano wire systems are in voltage controlled devices like BJT's and FET's, energy harvesting systems and biomedical sensing applications. Comsol Multiphysics has been used to calculate the bending of nano rods by applying Finite Element Method (FEM). The results obtained shows that the generated electric potential in the nano wire is independent of the length of the rod along z-axis and the surface piezoelectric potential generated is directly proportional to the displacement of the nanowire in the direction of force and inversely proportional to the cube of its length-to-diameter ratio. The piezoelectric potential generated due to the application of 100nN force on one end of the rod with the other end fixed is ~±2.3V which is suitable to drive gate voltages of various transistors and to be used in sensing applications.