Methods and articles used to degass liquids in a drop ejection device are disclosed. For example, a drop ejection device having a flow path in which fluid is pressurized for ejecting a drop from a nozzle opening, and a deaerator including a fluid reservoir region, a vacuum region, and a partition between the fluid reservoir region and the vacuum region, the partition including a wetting layer and a non-wetting layer and one or more channels extending through the wetting and non-wetting layers, wherein the wetting layer is exposed to the fluid reservoir region.
1. A drop ejection device, comprising: a flow path in which fluid is pressurized for ejecting a drop from a nozzle opening, and a deaerator including a fluid reservoir region, a vacuum region, and a partition between the fluid reservoir region and the vacuum region, the partition including a wetting layer and a non-wetting layer and one or more channels extending through the wetting and non-wetting layers, wherein the wetting layer is exposed to the fluid reservoir region.
2. The device of claim 1 , wherein the one or more channels have a width of about 0.1 micron to about 5 microns.
3. The device of claim 1 , wherein the one or more channels are through-holes.
4. The device of claim 1 , wherein the flow path and the deaerator are in a silicon material body.
5. The device of claim 1 , wherein the wetting layer has a surface energy of about 40 dynes/cm or more as determined according to the dynes test.
6. The device of claim 1 , wherein the wetting layer is a silicon material.
7. The device of claim 1 , wherein the non-wetting layer has a surface energy of about 25 dynes/cm or less as determined according to the dynes test.
8. The device of claim 1 , wherein the non-wetting layer is a polymer.
9. The device of claim 8 , wherein the polymer is a fluoropolymer.
10. The device of claim 1 , wherein the non-wetting layer has a thickness of about 2 microns or less.
11. The device of claim 1 , wherein the wetting layer has a thickness of about 25 microns or less.
12. The device of claim 1 , including a piezoelectric actuator.
13. The device of claim 1 , wherein the nozzle opening has a width of about 200 microns or less.
14. The device of claim 1 , wherein the device includes a plurality of fluid paths and a plurality of corresponding deaerators.