A valve system for an ocular implant device includes a boss structure. The boss structure includes an inlet for fluid inflow, and a number of outlets for fluid outflow. The valve system further includes a deformable membrane positioned over and spaced apart from the inlet, the membrane comprising a piezo-based material, an actuating element to apply pressure to the membrane to deform the membrane into a position that obstructs fluid flow from the inlet, and a control system to detect a position of the membrane based on measured electrical properties of the membrane.
