Abstract: A microvalve for controlling a fluid flow comprises a valve body provided with a valve opening having a sealing edge, and a valve plate provided with fluid openings. The valve plate is adapted to be moved perpendicularly to the valve body in such a way that, at a first position, said valve plate closes the valve opening, whereas, at a second position, it is perpendicularly spaced from said valve opening in such a way that a flow cross-section defined by said valve opening and said valve plate is decisively determined by the distance between the sealing edge and the valve plate. The contour of the sealing edge of the valve opening is chosen such that the length of the sealing edge exceeds the length of a sealing edge of a square valve opening which is equal in area.

Abstract: For a piezo valve (1) the sealable surface of the seat (13) of the controllable medium connection is so large that the pressure-induced closing force of the sealing region (14) of the bending element (4) that is generated in accordance with the medium pressure acting in the second switch position is greater than the elastically induced counterforce and smaller than the total of this counterforce and the piezo reset force acting upon application of a corresponding control voltage. Thus, both switch positions of the valve can also be held for a long period of time following pulsed voltage operation without any additional voltage application.