A novel nebulizer used in near dry machining systems for supplying cutting fluids and cooling air is presented. The nebulizer includes double-layer micro-nebulizers, each adopting piezoelectric transducer as the actuator, generating pressure in the chamber and ejecting liquid or air out of it. The mixture of cooling air and micro-partical spraying into cutting area has both the cooling and lubricating action. The design of the piezoelectric actuator and cavity structure, including the selection of the piezoelectric actuator type and materials is studied. The vibration modes are obtained by means of FEM.