Year: 2006
Type: article
Abstract: This paper describes a technique to eject liquid droplets in almost any direction with a nozzleless self-focusing acoustic transducer (SFAT) built on a ZnO thin film as well as on a thick PZT substrate. Sectoring of the SFAT annular rings of half-wave-band sources to create a piezoelectrically inactive area causes the droplet ejections to be directed non-perpendicular (i.e., oblique) to the liquid surface. The direction of the droplet ejections depends on the size of the piezoelectrically inactive area within the area of the half-wave-band sources. Droplets are ejected from the center part of the annular rings toward the open inactive area. Various openings up to 90° of pie shape have been made and tested to show that the ejection direction becomes less vertical as the piezoelectrically inactive area in the transducer increases. Additionally, a multi-directional ejector built on ZnO film has been demonstrated to eject micron-sized liquid droplets (several microns in diameter) in any of eight predetermined directions on demand . Larger size liquid droplets (about a hundred microns in diameter) have also been directionally ejected from a sectored SFAT built on a PZT substrate.
Authors: Jae Wan Kwon, Hongyu Yu, Qiang Zou, Eun Sok Kim
Institutions: University of Missouri, University of Southern California
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
Award: G1037014486
OpenAlex ID: W2070124681