This type of spray nozzle uses high (20 kHz to 180 kHz) frequency vibration to produce very narrow drop size distribution and low velocity spray from a low viscosity liquid. The vibration of a piezoelectric crystal causes capillary waves on the nozzle surface liquid film. The primary factors influencing the drop size produced are frequency of vibration, surface tension and density of the liquid.
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From applying flux to very precise areas on a circuit board to the application of carbon nanotubes on to touch-screens.
Pharmaceuticals and stent coating both benefit greatly from the ability to apply polymers and other materials with little to no losses. An ideal solution for applications requiring precise coatings using a very narrow spray pattern. Liquids are delivered through an external hypotube to the nozzle's atomizing surface. A low-pressure air stream through the nozzle's central orifice entrains the spray and produces tight, precise spray pattern. Spray width can be as low as 0.015" (0.4 mm) are possible. Soft, low-velocity atomized spray can be targeted with unmatched precision with minimal overspray (minimal waste). Ultra-low flow rates can be achieved over a wide range (from 0.3 - 9 ml/hour). Self-cleaning ultrasonic nozzle can prevent clogging.
Photovoltaic and dye-sensitized solar technology both need the application of liquids and coatings during the manufacturing process. With most of these substances being very expensive, any losses due to over-spray or quality control are minimized with the use of ultrasonic nozzles.
As manufacturing techniques get closer and closer to the atomic level, dipping parts and components in a bath is no longer viable. Extremely accurate spray will be needed more and more as technology shrinks to the point where processes can no longer be seen with the naked eye.
Berger, Harvey L. Ultrasonic Liquid Atomization: Theory and Application. 2nd ed. Hyde Park: Partrige Hill, 2006. 1-177.
Lefebvre, Arthur, Atomization and Sprays, Hemisphere, 1989, ISBN 0-89116-603-3