Tolerances Effect on Laser Structured Silicon-Based Multi Fourier-Horn Ultrasonic Nebulizer

Ultrasonic nebulizers have the ability to break liquid medicine into aerosols by generating standing waves at the surface of the liquid. Multi Fourier-horn ultrasonic nebulizer (MFHUN) was employed to atomize liquid by ultrasonic oscillation. UV femtosecond laser was used to structure the resonator layout on silicon wafer in order to fabricate MFHUN with reduced fabrication time and complexity. Piezoelectric transducer was manually placed on the resonator to excite longitudinal oscillation. The samples were characterized to investigate the effect of the fabrication process and the piezoelectric transducer placement tolerances on the ability of MFHUN to atomize liquid. The results showed that placing the piezoelectric transducer closer to the center of the drive section is required to increase the amplitude of the oscillation. The thickness of the adhesive layer beneath the piezoelectric transducer should not exceed 30 μm. Structures which showed amplitudes higher than the instability threshold atomized deionized water successfully.