Abstract: In some embodiments according to the present disclosure, methods for mitigating particle retention are provided including the use of frequency sweep excitation to eject particle in the sweep. In some embodiments according to the present disclosure, the acoustically driven fluid ejector can be capable of being switched between multiple modes of operation. In other embodiments according to the present disclosure, the acoustically driven fluid ejector can be altered such that it includes the capability to be filled with a biocompatible material to aid in the mitigation of particle aggregation in the acoustically driven fluid ejector. In some embodiments according to the present disclosure, the solid structure and number of nozzles of the acoustically driven fluid ejector can be adjusted such that the ejector of the acoustically driven fluid ejector can be self-pumping, i.e. no external pumping mechanism other than acoustics driven flow drag is used.

Abstract: Embodiments of the present disclosure provide a multistage procedure for treatment of biological samples (e.g., living cells with membranes, and the like) with a substance (e.g., a drug, DNA, RNA, plasmids, and other biomolecules or materials) to achieve more efficacious intracellular delivery and transfection.