| US 7,491,341 B2 | ||
| Method of making tapered capillary tips with constant inner diameters | ||
| Ryan T. Kelly, West Richland, Wash. (US); Jason S. Page, Kennewick, Wash. (US); Keqi Tang, Richland, Wash. (US); and Richard D. Smith, Richland, Wash. (US) | ||
| Assigned to Battelle Memorial Institute, Richland, Wash. (US) | ||
| Filed on Mar. 31, 2006, as Appl. No. 11/394,840. | ||
| Prior Publication US 2007/0235408 A1, Oct. 11, 2007 | ||
| Int. Cl. C03C 25/68 (2006.01); B44C 1/22 (2006.01) | ||
| U.S. Cl. 216—11 [216/83; 216/96; 216/97; 216/100; 216/108; 216/109] | 10 Claims |
| 1. A method of forming a tapered tip on a capillary tube having an inner surface, an outer surface, an inner diameter, an
outer diameter and an inner volume, the method comprising:
immersing a portion of the capillary tube into an etchant, wherein the etchant forms a concave meniscus on the outer surface
of the capillary;
flowing a fluid through the inner diameter of the capillary tube while etching the capillary tube until the immersed portion
is completely etched away;
wherein the inner diameter of the capillary tube is substantially constant and the outer diameter at the tip region is tapered.
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