Patent ID: 7465034

Claim:
An ink jet printhead comprising: a plurality of nozzles supported on a substrate; and at least one respective heater element corresponding to each nozzle, wherein each heater element is arranged for being in thermal contact with a bubble forming liquid, each heater element is configured to heat at least part of the bubble forming liquid to a temperature above its boiling point to form therein a collapsible gas bubble having a point of collapse, thereby to cause the ejection of a drop of the ejectable liquid through the nozzle corresponding to that heater element, the heater element generating the gas bubble from an electrical pulse having a duration less than 2 microseconds, and each heater element is configured such that the point of collapse of a bubble formed thereby is spaced from that heater element; wherein; each heater element includes solid material and is configured for a mass of less than 10 nanograms of the solid material of that heater element to be heated to a temperature above said boiling point thereby to heat said part of the bubble forming liquid to a temperature above said boiling point thereby to cause the ejection of a said drop.