A novel handhold high power MEMS atomizer using micro cymbal shape nozzle plate for inhalation therapy

Inhalation therapy is being applied in the home care field to a gradually increasing degree, and therefore two issues of great importance are the convenience and portability of medical devices. Hence, this paper presents a novel high-power MEMS atomizer device that includes a ring-type piezoelectric actuator and a cymbal-shaped micro nozzle plate (CSNP). The latter can focus energy on the center of the nozzle plate and induce a large force, which provides the MEMS atomizer with the high power necessary to spray medical solutions of high viscosity and increase the atomization rate. The high-power MEMS atomizer can reduce liquids to droplets of an ultra-fine size distribution (Mass Median Aerodynamic Diameter, MMAD), increasing the nebulizing rate and enabling the spraying of high-viscosity fluids (cP>3.5). In this research, the ultra-fine droplets were of a MMAD of less than 4.07nm at 127.89kHz and the atomization rate was 0.5ml/min. The drive voltage of this high-power MEMS atomizer device was only 3V, and the power consumption only one-tenth that of conventional ultrasonic atomizers at 1.2W. The simulation and experiments carried out in this study proved that the droplets are much smaller than those produced by current conventional devices and the device is of greater efficiency; therefore, the high-power MEMS atomizer is suitable for use in the development of a convenient and portable inhalation therapy device.