Surface acoustic wave atomizer

An application of a surface acoustic wave device for miniaturization of ultrasonic atomizers and for functional system construction is proposed. Actually, ultrasonic atomizers are rather smaller than those produced by other methods, so that nebulizers that are handy to carry use ultrasonic vibration. However, they are too large for a pocket or a catheter. A fine mist has been obtained with the first trial of a surface acoustic wave atomizing device whose dimensions are pocket size. There is a possibility of this functional device being reduced to a system of millimetre size. The atomizer consists of a vibrator, a cover and a tube. The vibrator and cover material are 127.8 degrees Y-cut LiNbO3 to generate a Rayleigh wave, a kind of surface acoustic wave. The Rayleigh wave is the driving force of the pumping and atomizing effects. The pumping effect is caused by the wave motion of the elastic material and viscosity of the fluid, like an ultrasonic motor. The atomizing rate varies according to the driving voltage. The maximum rate is about 0.6 ml min(-1) at around 10 MHz. The linear mean diameter is 19 mu m and the Sauter's mean diameter is 34 mu m. A smaller device that operates at 47 MHz is also demonstrated.