Abstract
In this work we show how to manufacture diamond sonic micronozzles. The advantage in using diamond to fabricate the micronozzles, compared with other materials, is that it is the hardest material known, has low thermal expansion, thermal conductivity is very high and it is chemically inert. In our process, tungsten wires, used as molds, have been fabricated by using an electrochemical etching process. These molds have been coated with diamond films by Chemical Vapor Deposition. By a wet etching, the tungsten mold was removed, obtaining the micronozzle. Flow measurements have shown that the diamond micronozzles work as passive flow controllers and flowmeters under choking conditions.