摘要 |
A wetting-resistant nozzle for accurately and precisely dispensing small volumes of liquids. The nozzle comprises an internal flowpath, and an external surface that recedes from the discharge point at an angle greater than 90 degrees, and an exceptionally low surface energy for the external surface. The low surface energy material may exist as a coating on top of a shaped substrate. A flat land region may be included and may have sharp edges, one of which may define the boundary of the low surface energy region. Another embodiment includes the low surface energy material as a bulk material through which a hole is drilled. The internal flowpath inside the nozzle may be smoothly tapered. Liquid being dispensed tends not to advance past the edge of the low surface energy region, which may coincide with a geometrically sharp edge. Such nozzles provide improved dispensing of liquids that have both low surface tension and low viscosity, such as organic solvents.
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