On-chip integration of eight directional droplet ejectors for inking a spot with eight droplets without ejector movement

This paper describes an on-chip acoustic ejector array consisting of eight directional droplet ejectors that was designed to ink a spot with eight different droplets without having to move the ejectors. Each of the eight directional ejectors consistently ejects uniform droplets in diameter of 51 μm with a directional angle about 17° (with respect to the normal direction of the liquid surface). When a glass substrate was placed 8 mm away from the ejector array chip, all the ejected droplets from the 8 ejectors were placed within 399 × 1080 μm² area. If we exclude two ejectors which had bad alignment with the others, all the 6 droplets were placed within 238 × 380 μm² area.