The disclosure relates to a piezo actuator device, preferably for controlling a dispensing of an application agent onto a component, including: at least one movable valve body for opening and closing at least one valve seat, at least one preferably pivotable actuating arm for actuating the at least one valve body, and a piezo actuator configured to move the at least one valve body to close and/or open the at least one valve seat.

A variable aperture assembly and a lens module thereof are provided. The variable aperture assembly includes a base, a rotating plate, multiple blades, and two driving modules. The rotating plate is located between the base and the blades, the blades are connected to the rotating plate having two tracks, and the two tracks respectively correspond to the two driving modules. The two driving modules are configured to leveragingly drive the rotating plate to respectively rotate in opposite directions, to drive the blades to correspondingly move. Each driving module includes a driving member and a driven member. When the driving member is controlled to apply a pushing force to the driven member, a stress-bearing portion of the driven member correspondingly generates a restoring force. The pushing force and the restoring force cooperatively drive the driven member to contact one of the two tracks. Therefore, an aperture may be accurately adjusted.