Device and method for coating surfaces
The present invention relates to devices and methods for coating surfaces including surfaces of medical devices, in particular the coating of microprojections on microprojection arrays. The present invention also relates to print head devices and their manufacture and to methods of using the print head devices for manufacturing articles such as microprojection arrays as well as to coating the surfaces of microprojection arrays. The present invention also relates to high throughput printing devices that utilize the print heads of the present invention.
1. A device for coating a substrate comprising:
a) a pumping chamber wherein a fluid is contained and wherein the pumping chamber has venting holes;
b) a restrictor plate which controls flow of the fluid;
c) a nozzle plate attached to the pumping chamber wherein the nozzle plate comprises a plurality of nozzles for dispensing the fluid, wherein the nozzle plate has venting holes which are in fluid communication with the venting holes in the pumping chamber and wherein the venting holes in the nozzle plate are straight and smaller in diameter than the nozzles;
d) a membrane plate; and,
e) a piezoelectric actuator wherein the actuator pushes against the membrane plate such that the fluid is dispensed through the nozzles.
2. The device of claim 1 , wherein the piezoelectric actuator is a piezoelectric unimorph actuator.
3. The device of claim 2 , wherein the pumping chamber further comprises one or more fluid ports by which the fluid is pumped into the pumping chamber.
4. The device of claim 2 , wherein the nozzles are made of at least one of:
a) etched silicon; or
b) electroformed nickel.
5. The device of claim 2 , wherein the device is aseptic.
6. The device of claim 2 , wherein the device is single use.
7. The device of claim 1 , wherein the venting holes in the nozzle plate and the venting holes in the pumping chamber are less than 50 μm in diameter.