Ejection Characteristics and Drop Modulation of Acoustic Inkjet Printing Using Fresnel Lens

Abstract

Acoustic Inkjet Printing uses an acoustic beam focused on a free liquid surface for drop ejection. This method can eject small drops without precise nozzle fabrication in comparison with thermal inkjet and piezoelectric inkjet. The fresnel lens was selected for focusing acoustic waves because of the precise and easy manufacturing by LSI process. The actual devise was made from a Si substrate and characteristics of its drop ejection were investigated. Furthermore, sound field by fresnel lens was calculated using Rayleigh's Equation to be compared with the experimental results that showed good agreement. Finally it was proved that acoustic inkjet printing with fresnel lens is suitable for drop modulation by utilizing second harmonic focus.