The on-demand ejection of ultra-fine droplets that uses both an electrohydrodynamic (EHD) force and mechanical actuation is presented. The liquid meniscus was controlled by a piezoelectric actuator, and the droplets were ejected by the EHD force. Through these effects, it was possible to obtain a high operational jetting frequency of 1 kHz with a short delay time (about 50 νs) in comparison with existing on-demand, EHD jetting methods, such as the pulsating jet mode (3-10 ms) and the pulsed cone-jet mode (3.6 ms). Simultaneously, we obtained ultra-fine droplets through adjustments of the piezoelectric driving waveform. The jetting characteristics were examined for both the hydrophobicity and the hydrophilicity of the surface of a capillary.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering