US Patent 7703697 - Nanotube bubblejet printer

http://www.freepatentsonline.com/7703697.html

This patent from Canon teaches a thermal inkjet printer designed to print aligned carbon nanotubes for applications such as field emitter display and transistor fabrication. Claim 1 reads:

1. A liquid discharge apparatus for discharging a disperse liquid containing a plurality carbon nanotubes, the carbon nanotubes having a length and a diameter, the liquid discharge apparatus comprising:

a nozzle having an entrance and a discharge opening through which the disperse liquid containing the carbon nanotubes is discharged;

an electrothermal converter for discharging the disperse liquid as an independent droplet from the discharge opening by applying energy to the disperse liquid and generating bubbles in the disperse liquid; and

a controller to apply electrical energy to the electrothermal converter, wherein the controller is configured to:

apply first electrical energy to the electrothermal converter that is sufficient to generate bubbles in the disperse liquid and discharge the disperse liquid from the discharge opening; and

at a time other than when the disperse liquid is being discharged from the discharge opening, intermittently apply second electrical energy that is smaller than the energy applied in discharging of the disperse liquid, to generate a plurality of bubbles in the disperse liquid and to vibrate the disperse liquid in the nozzle without discharging the disperse liquid from the discharge opening, the nozzle being tapered in such a manner that a diameter of the nozzle decreases from the entrance towards the discharge opening, and wherein the diameter of the entrance is larger than the length of the carbon nanotubes, and the diameter of the discharge opening is larger than the diameter of the carbon nanotubes and smaller than the length of the carbon nanotubes.