A technique for designing a parasitic patch antenna array whose beam can be steered dynamically using a fluidic tuning mechanism is presented. Using this technique, a three-element patch antenna array operating at 5 GHz is designed and fabricated using 3D printing. Two oil-filled channels are placed in the substrate of the antenna along the radiating edges of the patches andfilled with movable metal cylinders and glass balls. The parasitic elements are mutually coupled to the centre element in the H-plane. As the train of metal cylinders and glass balls are moved from the left or right with respect to the centre-driven patch element, the beam is steered towards the opposite direction. The proposed parasitic patch array is able to steer the beam 22.5 with maintained impedance matching.