An inkjet printing device includes an ink reservoir containing ink and having an outlet through which the ink passes for ejection onto a print medium; a micro-fluidic actuator having at least (i) an inlet channel through which fluid enters; (ii) a chamber through which the fluid is received from the inlet channel; (iii) an outlet channel that receives the fluid from the chamber and passes the fluid through the outlet channel so that a conduit pathway for the fluid is formed from the inlet channel, chamber and outlet channel; (iv) a flexible member that forms a portion of a wall of the chamber and that displaces in response to fluidic pressure; (v) at least a first valve in the conduit pathway which, when the valve is activated, causes flow of the fluid through the conduit pathway to be altered so that pressure of the fluid passing through the chamber changes which, in turn, causes the flexible member to displace which, in turn, causes the ink to be ejected or not ejected from the ink reservoir according to the displacement of the flexible member.