Abstract: A micro pump is formed on a substrate having a common inlet channel and a common outlet channel by a plurality of pumping elements, each pumping element having an inlet coupled to the common inlet channel and an outlet coupled to the common outlet channel, the inlet and outlet connected by a microfluidic channel, the microfluidic channel comprising a valvular conduit having low fluid flow resistance in a direction from the inlet to the outlet and high fluid flow resistance in a direction from the outlet to the inlet, and an actuating element arranged to cause fluid to be pumped through the microfluidic channel from the inlet to the outlet, wherein the actuating element is based on one or more of piezoelectric, thermal, electrostatic or electromagnetic transduction. A controller is coupled to actuate the actuating elements at mutually staggered relative timing so as to produce a substantially continuous steady flow.

Abstract: A micro pump is formed on a substrate having a common inlet channel and a common outlet channel by a plurality of pumping elements, each pumping element having an inlet coupled to the common inlet channel and an outlet coupled to the common outlet channel, the inlet and outlet connected by a microfluidic channel, the microfluidic channel comprising a valvular conduit having low fluid flow resistance in a direction from the inlet to the outlet and high fluid flow resistance in a direction from the outlet to the inlet, and an actuating element arranged to cause fluid to be pumped through the microfluidic channel from the inlet to the outlet, wherein the actuating element is based on one or more of piezoelectric, thermal, electrostatic or electromagnetic transduction. A controller is coupled to actuate the actuating elements at mutually staggered relative timing so as to produce a substantially continuous steady flow.

Abstract: Droplet deposition apparatus comprises a fluid chamber comprising an actuator actuable by electrical signals to effect ejection of droplets from the fluid chamber, a drive circuit for supplying the electrical signals; and a conduit for supplying droplet fluid to said fluid chamber, the drive circuit being in substantial thermal contact with the conduit so as to transfer a substantial part of the heat generated in the drive circuit to the droplet fluid.

Abstract: A piezoelectric printhead or other droplet deposition apparatus has parallel liquid containing channels defined by a base and displaceable walls, and covered by a cover number. The channels each have at least one nozzle for ejecting droplets. Each nozzle may be disposed in the base, the cover then having two ink supply parts spaced lengthwise of each channel on opposite sides of the nozzle. Alternatively two longitudinally spaced nozzles may be provided in the base of each channel. The cover may have a conductive track corrected to wall-displacing electrodes, the points of connection being outside the channels.

Abstract: An inkjet printhead has ink channels separated one from the next by channels walls that are displaceable in response to actuating signals. Groups of adjacent channels are supplied by respective manifolds such that a single displaceable wall bounds channels belonging to adjacent channel groups. A simplification of the construction and manufacture of the printhead results.

Abstract: In a method of making an ink jet printhead, corrugations are formed by laser ablation in the bonding surface of a polymer nozzle plate. Adhesive is applied to the micro-cavities thus formed and the nozzle plate is pressed against the end surface of the printhead until the surface lands in the nozzle plate abut on the surface of the printhead.

Abstract: Ink jet printhead components are formed initially by bonding together a grooved base wafer and a suitable cover wafer, the area of the bonding wafer assembly being sufficient to provide a 14.times.14 array of components. Using a datum formation, the wafer assembly is divided into strips and linear processing steps are conducted, such as applying nozzle plates and laser ablating nozzles. Each strip can then be divided to form separate printhead components.

Abstract: As a step in the manufacture of an ink jet printer, a cover (16) is adhesively bonded to a piezoelectric layer (10) having parallel grooves (20) which will serve as ink channels in the finished printer. Mating surfaces are prepared, excess adhesive is applied and bond pressure exerted until surface extremities of the two surfaces come into contact, producing a bond layer of 2 .mu.m or less. To ensure that the flow distance of excess adhesive is uniform over the bond plane, grooves (32) are cut at the margin (30) of the piezoelectric layer.