Droplet generation using a torsional Langevin-type transducer and a micropore plate

This paper reports on droplet generation by using a torsional bolt-clamped Langevin-type transducer and a micropore plate. When the micropore plate was not oscillated, droplets were generated irregularly. On the other hand, when the micropore plate was oscillated, droplets were generated regularly. In addition, by changing the micropore diameter, the generated droplets’ diameter was varied in proportion to the micropore area. Under the condition that the pore diameter, the vibrational amplitude and the resonance frequency were 16 μm, 0.62 μmp–p and 56 kHz, respectively, the average diameter of droplets was 26.8 μm and the standard deviation was 1.4. Additionally, W/O (water-in-oil) emulsions were generated in air–liquid phase by the transducer. Under the same condition, generated average diameter of emulsions was 35.0 μm, the standard deviation was 1.9 and the coefficient of variance was 5.5. From this result, monodisperse emulsions were generated.