Investigations on electrohydrodynamical drop-on-demand inkjet printing

The effects of electrohydrodynamical (EHD) drop-on-demand inkjet variables on the droplet diameter are presented in this paper. The EHD printer uses a high pulsed voltage to generate strong electric field in the vicinity of the apex of the dome-shaped liquid meniscus and thus micro-jetting ejection of droplet comes forth. And the liquid shaping processes are revealed through CCD. The droplets with 50 mum diameter were formed on the silicon collector. We have evaluated systematically the effects of EHD inkjet printing design variables such as the voltage, the frequency, the solution concentration, the voltage duty cycle and the contact angle on the droplet diameters. The experiment results show the droplet diameters get larger with the voltage, the solution concentration and the voltage duty cycle increasing respectively. And when the frequency, the contact angle increases respectively, the droplet diameters get smaller.