Patent ID: 7641325

Claim:
An apparatus for characterizing fluid droplets formed from a non-conductive fluid jet comprising: a nozzle channel; a pressurized source of a non-conductive fluid in fluid communication with the nozzle channel, the pressurized source being operable to force a jet of the non-conductive fluid through the nozzle channel; and a characterization electrode, at least one portion of the characterization electrode being electrically conductive and initially in intimate contact with a first portion of the non-conductive fluid jet and thereafter in intimate contact with a second portion of the non-conductive fluid jet, the at least one electrically conductive portion of the characterization electrode being initially in intimate contact with the first portion of the non-conductive fluid jet to transfer a first electrical charge to a region of the first portion of the non-conductive fluid jet that stimulates the non-conductive fluid jet to form a first fluid droplet and being thereafter in intimate contact with the second portion of the non-conductive fluid jet to transfer a second electrical charge to a region of the second portion of the non-conductive fluid jet that stimulates the non-conductive fluid jet to form a second fluid droplet, wherein a first fluid droplet formed from a first portion of the non-conductive fluid jet has a first characteristic determined by the first electrical charge transferred to a region of the first portion and a second fluid droplet formed from a second portion of the non-conductive fluid jet has a second characteristic different than the first characteristic and determined by the second electrical charge transferred to a region of the second portion.