Electrical & Computer Engineering, Department of


Date of this Version



United States Patent US 7,972,560 B2 Jul. 5, 2011


US govt. doc. Public Domain


An apparatus capable of dispensing drops of material with volumes on the order of Zeptoliters is described. In some embodiments of the inventive pipette the size of the droplets so dispensed is determined by the size of a hole, or channel, through a carbon shell encapsulating a reservoir that contains material to be dispensed. The channel may be formed by irradiation with an electronbeam or other high-energy beam capable of focusing to a spot size less than about 5 nanom eters. In some embodiments, the dispensed droplet remains attached to the pipette by a small thread of material, an atomic scale meniscus, forming a virtually free-standing droplet. In Some embodiments the droplet may wet the pipette tip and take on attributes of supported drops. Methods for fabricating and using the pipette are also described.