Technique for Producing Capillaries with Reproducible Orifice Diameters for Uniform Droplet Generation

Abstract

A procedure is described for fabricating capillary orifice tips useful for the generation of uniform droplets. These generator tips operate at relatively low applied pressure, are relatively resistant to clogging, and incorporate orifice diameters reproducible to 1%. The method involves implanting a fused-silica capillary within a glass sleeve. When heated, the glass and fused silica wet to form a tight seal with no cracking caused by differences in thermal expansion. This technique permits the routine production of capillary tips with fixed orifice and outer diameters.