Development of a Multi-Color Material Jetting Technique

Nozzleless ejectors capable of multi-color material jetting are proposed. Compared to the state of theart, the proposed technique offers an alternative, where the ejectors will not be stuck by the UV resin andmulti-color prototype can be carried out. The proposed nozzleless ejectors are built on a piezoelectric filmwith top and bottom electrodes. The electrodes will be patterned into annular rings to form the acousticFresnel lens, so that the acoustic waves generated by these annular zones could interfere constructively atthe focal point. The acoustic wave can be focused into tens or hundreds of microns or even smaller bydifferent excitation frequencies, thus the UV resin can be ejected. In this proposal, the ejecting angle can beadjusted by adequately arranging the locations and shapes of the individual ejector. The acoustic gradienttheory will be used to optimize the droplet size, ejecting velocity, and the ejecting angle. By constructing thearrayed ejector module, high precision multi-color model without supporting structures can be realized. Theproposed micro ejector module is compatible with the semiconductor processes. With the MEMS packagingtechniques, the system can incorporate the ejector array with micro fluidic channels for multi-color materialjetting.