Abstract: The weak form of governing equations,impermeable boundary conditions of the crack face and reciprocity conditions at the interface of different piezoelectrics for sectorial biomaterial domains is derived.By using the eigenfunction expansion technique and the weak form,a special one-dimensional finite element formulation is developed to determine singularities of electromechanical fields at the crack tip in piezoelectrics.Discretization in angular coordinate is needed only and the global equation is a second order characteristic matrix equation.The formulation is verified by comparing the computed results with the existing analytical solution.Accurate solutions are produced by very few elements.The singularities of electromechanical fields at the interfaces of bimorph are studied.