A valve assembly includes a flexible sheet actuator in which two piezo sheets are stacked and actuated in opposite senses to form a bending assembly. The inner faces of the first and second sheets of piezoelectric material are laminated to respective conductive lead paths on opposite sides of a two-sided flex circuit, and the outer faces of the sheets of material are each covered by and electrically contacted to another flex circuit to produce a totally enclosed flat bender. At least a portion of the flex circuits extend away from the bender to provide a flexible and robust conductive lead-in thereto. The electrical connection is a flat ribbon-like strip of lesser thickness than the bender, and may pass hermetically between a gasketed or sealed face and cover plate of the valve. The middle layer of the bender construction is an insulating film, and a narrow lead pattern on each side of the film provides an extended electrode contact path to each of the opposing piezo sheets while allowing the two sheets to act against each other through the film, achieving a high level of bending actuation. The actuator is an essentially planar assembly which both insulates the piezo electric elements and allows them to be cantilevered from a housing with a simple flat clamping plate. The electrode paths extending outside the clamped region may connect to one or more adjacent piezo elements, forming a multi-actuator strip assembly. Holes are punched through the assembly away from the piezo elements or lead paths to provide registration or to accommodate mounting bolts.