Digital Microinjection Technique Driven By Piezoelectric Actuator

This paper presents a novel microinjection technique, by which microfluidic delivery, transport and control can be digitally realized. The microinjection bases on a new principle that the microchannel is driven by a piezoelectric actuator. The piezoelectric actuator connected to the solid wall of the microchannel exerts a periodicity disturbing on the solid wall and the boundary flow obtains a movement along with the solid wall. Then the viscous force within the liquid transfers the movement, in consequence; the microfluidic body obtains a movement. The validity of the presented principle is verified by experiments. Digital microinjection has been realized, particularly under conditions that neither micro moving parts nor embedded micro electric circuits are necessary, hence greatly simplifying the structure and reducing the cost. The volumes of each injection droplet are controllable and uniform. The kinds of the fluid materials that can be injected include conventional liquids as well as solid powders, pastes, and other substances of similar characteristics.