Abstract: The invention relates to a micropump (10; 100) comprising at least a first plate (12), a second plate (20), an intermediate plate (18), a pump chamber (24), and inlet and outlet control members (28, 30). According to the invention, said inlet control member (28) is a non-return valve situated in the major portion of the thickness of said intermediate plate (18), being made of a moving member (40) and a membrane-forming portion (42) situated close to one of the plates (12, 20), connecting said moving member (40) to the remainder of said intermediate plate (18) and, by its resilience, enabling said valve (28) to move between a closed position and an open position, said moving member (40) having an orifice of limited volume passing therethrough.

Abstract: A micropump including at least one main plate (1), at least one upper plate (2), and a middle plate (3) arranged between the other two plates (1, 2) and forming a pumping chamber (4) that is connected with at least one inlet of the micropump and at least one outlet of the micropump. The pumping chamber comprises a movable wall (5) machined into the middle plate (3); the upper plate is equipped with at least one opening (12) linking a cavity (8) with at least one portion of the movable wall (5). Actuation devices (6, 7, 13) attached to the free surface of the upper plate (2) are used to shift said movable wall (5) in order to bring about a periodic variation in the volume of the pumping chamber (4). According to the invention, the actuating devices (6, 7, 13) are formed by an actuating plate (7) of a material which can be machined so as to define a movable area (11) and said cavity (8).

Abstract: The invention relates to a micro-machined fluid-flow device (10) comprising a substrate (12) possessing a flow duct (14), a deformable thin layer (18) such a pump membrane or a valve-forming membrane. According to the invention, the thin layer (18) is a rolled metal sheet, preferably made of titanium, and connected to the substrate (12) in the zone (20) overlapping the flow duct, by an anodic bonding. The invention is applicable to making a valve.

Abstract: The micropump (11) has at least two first plate-forming means (10, 12) together defining a pump chamber (9), and the filter comprises liquid feed means, liquid collection means, second plate-forming means (10), and silicon plate-forming means (12; 15), said second plate-forming means (10) and said silicon plate-forming means (12; 15) facing each other and forming between them a cavity (13) for receiving a liquid, the cavity being partially closed by at least one transverse partition (20; 20') whose height is less than the depth of the cavity (13) and which separates it into an upstream portion and a downstream portion. Said silicon plate-forming means (12; 15) are fixed at least partially in leakproof manner to said second plate-forming means (10), the downstream portion of the cavity (13) communicates with said pump chamber (9), and the assembly comprising all of the plate-forming means (10, 12) constitutes a sandwich structure.

Abstract: A micropump including two glass sheets (2, 8) with a machined silicon board (6) sealingly inserted therebetween. An inlet valve (12), a pumping chamber (50) and an outlet valve (28) are arranged between an inlet (10) and an outlet (4). A pump diaphragm (56) forming one wall of the pumping chamber comprises a thickened central portion (58) interacting with the upper sheet (8) to form an abutment restricting the suction movement of the diaphragm (50), and lower abutment elements (60) restricting the movement of the diaphragm when the fluid is discharged. A piezoelectric pad (72) engages the diaphragm by means of an intermediate part (84) to perform the pumping movement between upper and lower limits precisely defined by the abutments. A precisely defined and constant flow rate is thus achieved regardless of changes in the performance of the piezoelectric pad.

Abstract: A micropump including two glass wafers (2, 8) with a machined silicon wafer (6) sealingly inserted therebetween. An inlet valve (12), a pump chamber (14) and an outlet valve (16) are arranged between an inlet channel (4) and an outlet channel (5). A pump diaphragm (36) forming one wall of the pump chamber comprises a thicker central portion (38) operating like a piston. A piezoelectric element (52) acts on the diaphragm via an intermediate part (64) to provide the pumping movement. The pump chamber (14) and the spaces (22, 24) linking the pump chamber to the inlet and outlet valves are shaped so that the reduction in the inner volume of the micropump caused by a reduction in the volume of the pump chamber during the pumping movement is such that the air in the micropump is compressed to a pressure high enough to open the outlet valve, whereby the micropump is self-priming.

Abstract: An adhesive patch for delayed onset transdermal drug delivery, comprising a reservoir or matrix containing the drug. An impervious membrane is arranged on said reservoir or matrix and designed to become pervious after a given delay period by receiving an external stimulus that alters its physical/chemical structure.

Abstract: Flat-bottomed cavities are formed in a substrate (2) by a method comprising two etching steps: a first anisotropic etching through a mask (4) leaving exposed bands (6,8) of the substrate (2) and a second anisotropic etching through a mask leaving exposed all of the zones (Z1, Z2) to be etched. The first etching provides grooves in V form (10,12), the depth of X.sub.1, X.sub.2) which depends on the width of the bands, while the second etching increased the depth of the cavities by the same amount y, in eliminating the bands located between the grooves. Advantage: flat cavities of different depths may be obtained simultaneously.

Abstract: A valve is formed by machining a silicon wafer 18 bonded to a glass wafer 2. This machining forms a membrane 44 and a sealing ring. Part of the surface of the membrane 44 and optionally the sealing ring are oxidized in order to impart a mechanical pre-tension to the membrane holding the valve in a closed position. Further etching 52 may be carried out in a manner such that in the absence of the aforesaid pre-tension the valve is in the open position at rest.

Abstract: A valve is formed from a silicon wafer (20) and has a position detector to detect by contact the position of the valve and hence reveal any malfunction. The position detector comprises a first electrical contact (54) formed on a glass support (32) mounted on the back face of the wafer (20), a second electrical contact fixed to the wafer (20) and an electrical impedance measurement circuit (resistance or capacitance according to the embodiment) between the two electrical contacts. The valve is useful in a micropump for the injection of medicaments.

Abstract: A micropump comprising a pumping chamber, an inlet channel communicating with the pumping chamber by an inlet valve and an outlet channel communicating with the pumping chamber via an outlet valve, these elements being manufactured by etching a silicon wafer is then sealed to glass wafers, the micropump also comprising a piezoelectric wafer to vary the volume of the pumping chamber by bending a wall forming part of the wall of this pumping chamber. In accordance with the invention the pumping chamber has a stop which determines the amplitude of movement of the flexible wall. The variation in the volume of the chamber caused by the displacement of the flexible wall is precisely defined, thus making it possible to maintain the output of the micropump constant during normal operating conditions.