This study presents an E-FEM/L-S approach for modeling fluid-fluid inter-face deformation in microsystems under electric fields. The approach treats the interface as a zero-thickness boundary and precisely models discontinuities in pressure and elec-tric fields. Numerical results show improved accuracy on coarser meshes compared to conventional methods. The proposed model is useful for problems without guaranteed symmetry of revolution and can efficiently analyze fundamental aspects of multi-phase microsystems.