Design and Fabrication of Micro Droplet Generator

Micro-droplet formation for drop-on-demand (DOD) has many applications such as ink-jet printing, rapid prototyping, and metal powder producing. In this paper design and fabrication of micro droplet printing actuator using piezoelectric excitation is presented. Piezoelectric vibration is used to push liquid out of nozzle and produce droplets. Effect of voltage amplitude, suction and pressure time and nozzle diameter on droplet diameter is investigated. Also, effect of voltage amplitude on droplet velocity and cut off length is described. Presented results can be used to control droplet properties. High speed camera is used to evaluate droplet diameter and velocity. High speed camera pictures are processed with MATLABR2008a. It is possible to control droplet diameter from 450 to 1000 micron with presented actuator. Velocity of droplet can be also controlled in range of about 0.2 to 1.4 m/s. At last, for testing repeatability, ink printing on paper attached to rotary table is done.

Keywords:

Droplet , Drop-on-demand printing , Nozzle , Piezoelectric