Computational simulations are conducted to investigate the fluid dynamics of flapping wings at ultra-low Reynolds numbers for micro-aerial vehicle applications. Rigid solid wing and ‘comb’-like of the same planform and the equal thicknesses are considered in the current study. Incompressible flow simulations are carried out to compute flowfield and aerodynamic forces on the wings for two types of wing kinematic motions. A parametric study of geometric and kinematic parameters is also conducted to compare the two wings. The aerodynamic forces for Solid wing and the Comb wing are found to be quite similar at lower Reynolds number however the detailed examination of the forces showed that the force generation mechanisms on the two wings are quite different. Analysis suggests that the Comb wings can provide a significant weight savings with a minimal loss in the aerodynamic performance for ultra-low Reynolds number applications.