Plasma actuators are electronic devices commonly used for active flow control. These devices have been shown to be effective in a wide variety of fluids engineering applications. In order to increase the efficiency of these devices, the combination of micro-exposed electrodes with stair-shaped dielectric layers is proposed. The flow induced by micro- and macrostair-shaped plasma actuators is experimentally evaluated and its mechanical efficiency is estimated. Furthermore, durability tests are performed in order to show that stair-shaped dielectric layers also allow to increase the device lifetime. It is shown that by combining micro-exposed electrodes with stair-shaped dielectric layers, it is possible to achieve mechanical efficiencies eight times greater than in a conventional macro-actuator. In addition, degradation tests demonstrate that stair-shaped dielectric layers degrade slower and lead to an increased lifetime.